Looking to learn more about your boiler? Take a look at our comprehensive guide on how to reset a boiler. Featuring Baxi, Vaillant, Ideal and Worcester Bosch.

<p>The wonderful world of <a href="https://www.boxt.co.uk/boilers" rel="follow">boilers</a>. These domestic workhorses are the household's unsung heroes, especially during the winter months.</p>
<p>When it comes to your heating system, it pays to know your way around it. This way, if any issues arise, you'll have a better idea of how to tackle them and get your home running as it should once again.</p>
<p>A handy tip in boiler maintenance is knowing how to reset your boiler. Below, we'll go through some of the most common models on the market today and how to reset them when the need presents itself.</p>
<h2>Safety precautions</h2>
<p>Resetting a boiler using the controls is not classed as working on the boiler, so homeowners can safely do this. Any more in-depth work must be performed by a qualified, Gas Safe registered engineer. If a problem persists after resetting the boiler, you should <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a Gas Safe engineer</a>, as there might be an underlying issue that resetting alone won&rsquo;t resolve.</p>
<h2>Signs your boiler might need to be reset</h2>
<p>It&rsquo;s important only to reset your boiler when something is actually wrong, which means it&rsquo;s important to be able to recognise the telltale signs of an internal issue somewhere in the system.</p>
<p>Here are some of the most common symptoms to look out for as a signal to reset your boiler.</p>
<ul>
<li><strong>No heating or hot water</strong>: If your boiler isn't performing as it should, it may benefit from a reset.</li>
<li><strong>Error codes</strong>: Fault or error codes are a great way to identify an issue with your boiler. If you check your boiler's manufacturer's notes, it may suggest resetting the boiler to tackle an error code.</li>
<li><strong>Thermostat malfunction</strong>: The boiler thermostat can sometimes stop working in sync with the system. Resetting the boiler can help get things working as they should.</li>
<li><strong>A power cut</strong>: If your home has suffered a power outage, there's a good chance your boiler will need to be reset, as it could have forced a boiler lockout.</li>
</ul>
<p>Whilst these symptoms can often be remedied with a simple reset, it is crucial that you do not carry out any work on your boiler. <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Get in touch with a Gas Safe registered engineer</a> if any issues with your boiler persist so they can investigate further and resolve any issues you still have.&nbsp;</p>
<h2>How to reset a Baxi boiler</h2>
<p>Baxi boilers tend to be able to be reset in three different ways, depending on their design. These are as follows.<br>Resetting a Baxi boiler with a reset button<br>In this scenario, press the reset button and hold until you can hear the boiler resetting.</p>
<h3>Resetting a Baxi boiler with a thermostat control knob</h3>
<p>Turn the thermostat control knob anticlockwise. Hold until the red lockout light turns off, and then turn back to your desired setting.</p>
<h3>Resetting a Baxi boiler with an ON/OFF/SELECTOR switch</h3>
<p>Here, you must open the pull down panel to show the full control panel.</p>
<p>To reset the boiler, you need to turn the selector switch to the R (Reset) position, hold for at least 5 seconds, and release.</p>
<p>Visit the manufacturer&rsquo;s website for more information on <a href="https://www.baxi.co.uk/faqs/how-to-reset-a-baxi-boiler" rel="follow noopener" target="_blank">resetting Baxi boilers</a>.</p>
<h3>How to reset an Ideal boiler</h3>
<p>With Ideal boilers, most of the reset buttons can be found beneath the display screen. For boilers with a digital display, you will likely find the reset option in the "settings" section of the menu. You can find exactly where the reset button is if you take a look at the manufacturers' notes.</p>
<p>Below are some of the top models from Ideal's range and how to reset them.</p>
<h3>Resetting Ideal Espirit Eco 2 boilers</h3>
<p>To reset this boiler, press the select and arrow up button for 2 seconds at the same time.</p>
<h3>Resetting Ideal Logic boilers</h3>
<p>Press the reset button on the front of the boiler. It will then repeat its ignition sequence.</p>
<h3>Resetting Ideal Logic + boilers</h3>
<p>The reset button is below the digital display. Press it once.</p>
<h3>Resetting Ideal Vogue Max boilers</h3>
<p>Press the reset button underneath the digital display.</p>
<p>Read our blog on <a href="https://www.boxt.co.uk/boilers/guides/how-to-restart-or-reset-ideal-boilers" rel="follow">resetting your Ideal boiler</a> or visit <a href="https://idealheating.com/user-guides" rel="follow noopener" target="_blank">Ideal&rsquo;s website</a> for more information.</p>
<h2>How to reset a Navien boiler</h2>
<p>With <a href="https://www.boxt.co.uk/boilers/navien-boilers" rel="follow">Navien boilers</a>, the reset button is often located on the front panel, near the control display screen. Below are some of the top models in their range and specifics on how to reset them.</p>
<h3>Resetting Navien NCB300 boilers</h3>
<p>Resetting this boiler is as simple as pressing the power button. Failing this, consult the manufacturer's notes.</p>
<h3>Resetting Navien LCB700, NCB700, &amp; NCB500 boilers</h3>
<p>Press the back button to reset the LCB700, NCB500 and NCB700 boilers. If the boiler does not restart, look at the manufacturer's notes.</p>
<h3>Resetting Navien NCB-24LDWE boilers</h3>
<p>To reset this model, press the reset button on the boiler's front panel.</p>
<p>We have a dedicated blog for <a href="https://www.boxt.co.uk/boilers/guides/navien-boiler-reset" rel="follow">resetting Navien boilers</a>, so be sure to read on for more information on the topic. To learn more about resetting other Navien models, you can check <a href="https://navien.co.uk/support/manuals-and-brochures/" rel="follow noopener" target="_blank">Navien&rsquo;s boiler page</a> directly.</p>
<h2>How to reset a Vaillant boiler</h2>
<p>The boiler reset button on most Vaillant models is located on the boiler's display and will show an icon of a flame with a line crossed through it.</p>
<p>To reset a Vaillant boiler, you need to hold this button down for three seconds. You will know it has worked as the display screen will change, and you will hear the boiler reset.</p>
<p>While this is the case for most Vaillant boilers, it always makes sense to check your user manual or the <a href="https://www.vaillant.co.uk/advice/understanding-heating-technology/boilers/how-to-reset-a-boiler/" rel="follow noopener" target="_blank">Vaillant website</a> if you are unsure.</p>
<h2>How to reset a Worcester Bosch boiler</h2>
<p>If your Worcester Bosch boiler has stopped working properly or the blue light on the front of the system is flashing, it may be worth trying a reset.</p>
<p>There are some subtle variations in methods from model to model, so we'll outline the steps for the most common Worcester Bosch boilers below.</p>
<h3>Resetting Worcester 4000 boilers</h3>
<p>On the digital display, scroll using the up and down keys until you see the word "reset". Press that, and the boiler should restart at its current temperature.</p>
<h3>Resetting Worcester Greenstar Si, i &amp; CDi Compact Boilers</h3>
<p>Press the reset button. A tick should briefly appear.</p>
<h3>Resetting Worcester Greenstar CDi Boilers</h3>
<p>Hold the reset button for three seconds.</p>
<p>The blue light flashing will stop at the reset button and fault indicator. If the reset is successful, the boiler will start again. If not, an alert code will display, in which case you should get in touch with a qualified engineer.</p>
<h3>Resetting Worcester Greenstar Ri boilers</h3>
<p>If there is a fault, the blue mains light will flash.</p>
<p>To reset, turn the central heating temperature knob clockwise until it reaches the &ldquo;RESET&rdquo; position. Hold the button down for 5 seconds and then return to the original temperature setting.</p>
<p>The boiler should reset.</p>
<p>If the boiler you&rsquo;re looking for isn&rsquo;t on this page, take a look at <a href="https://www.worcester-bosch.co.uk/support/manuals-and-brochures" rel="follow noopener" target="_blank">Worcester Bosch&rsquo;s manual and brochures</a> page for further information.</p>
<h2>Replace your boiler with an A-rated model from BOXT</h2>
<p>If you&rsquo;re having to reset your boiler regularly, you could be due a <a href="https://www.boxt.co.uk/boilers/boiler-replacement" rel="follow">new boiler</a>. Find the perfect upgrade for your home with BOXT. We supply a range of A-rated boilers that deliver on efficiency, usability, and price.</p>
<p>Rather not pay it all at once? We understand. Take a look at our <a href="https://www.boxt.co.uk/boilers/subscription" rel="follow">boiler subscription</a> offering, where you can heat your home with a brand-new system for as little as &pound;30 a month.</p>
<p>If you aren&rsquo;t sure where to start, <a href="https://www.boxt.co.uk/contact-us" rel="follow">get in touch</a> with one of our team to find out how we can help your home reach optimal performance.</p>

Find a new, A-rated boiler for your home in just 90 seconds with us

How to reset a boiler

Explore Viessmann boiler fault and error codes and other common boiler issues, like how to repressurise and connect a Viessmann boiler to your Wi-Fi. 

<p>If your Viessmann boiler has stopped working, it can be frustrating, especially if it leaves you without hot water or central heating. To give you an idea of what the problem is, however, an error code will likely be displayed on your boiler&rsquo;s interface.&nbsp;</p>
<p>Viessman <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> fault codes are designed to ensure problems can be diagnosed more quickly, meaning boiler technicians can get your system back up and running more quickly.&nbsp;</p>
<p>To further reduce the time you&rsquo;re left without a functioning boiler, we put this handy guide together so you&rsquo;re not left wondering what&rsquo;s wrong for too long.&nbsp;</p>
<h2>Viessmann fault &amp; error codes by code</h2>
<ul>
<li><a href="#h_232222911108511708094670745" rel="follow">Fault code 5C, 5D, 5E and 5F</a></li>
<li><a href="#h_290959891113001708094726577" rel="follow">Fault code 10</a></li>
<li><a href="#h_941642352115971708094750788" rel="follow">Fault codes F6, 58, F9, F-E1, F-E2 and F-F6</a></li>
<li><a href="#h_78984742118971708094774703" rel="follow">Fault codes 18 and D1</a></li>
<li><a href="#h_497828654121081708094804479" rel="follow">Fault code A4</a></li>
<li><a href="#h_889068054124051708094825684" rel="follow">Fault code OC</a></li>
</ul>
<h2>How to reset a Viessmann boiler</h2>
<p>The way to reset your boiler will vary depending on your Viessman boiler. You may need to turn a dial or press a series of buttons. Make sure to check your boiler&rsquo;s manual for specific instructions relating to your system.&nbsp;</p>
<p>Before resetting your boiler, you must check which fault code is displayed to determine whether you can fix the problem. For example, if your boiler has locked you out because the pressure is too low, this is something you can remedy yourself. You must not attempt difficult or complex repairs, though. Anything requiring more than a simple fix must be repaired by a qualified Gas Safe registered engineer.&nbsp;</p>
<h2>How to increase pressure on a Viessmann boiler</h2>
<p>Most Viessman boilers have an operating pressure of 1-1.5 bar. This is usually shown as a green zone on the pressure gauge.&nbsp;</p>
<p>On Viessmann system and combi boilers, the pressure gauge can be found in the control panel. Meanwhile, for standard (regular or heat-only) boilers, the pressure gauge is fitted in the pipework just below the boiler.&nbsp;</p>

Discover everything you need to know about combi, standard and system boilers

Check out our complete guide

Not sure which type of boiler you have?

<p>Before increasing the pressure on your boiler, you should consult the boiler&rsquo;s instructions for specific guidance and ensure you feel comfortable <a href="https://www.boxt.co.uk/boilers/guides/boiler-pressure" rel="follow">repressurising the boiler</a> yourself. If you are in any doubt about what to do, always contact a Gas Safe registered engineer for help.</p>
<p>If you feel confident in repressurising your boiler, follow the instructions below.</p>
<ol>
<li>Locate the filling loop and pressure gauge - filling loop handles should be at a 90o angle to the flow direction of the pipe.</li>
<li>Make sure you can see the pressure gauge once you find the filling loop. This will help you ensure you&rsquo;re not over- or under-filling the pressure gauge.</li>
<li>The correct pressure level will be shown in green.</li>
<li>Turn the boiler off.</li>
<li>Turn the filling loop handles so they match the direction of the pipe. You should hear water flowing when you do this.</li>
<li>Remember to keep an eye on the pressure gauge so you don&rsquo;t add too much pressure. Once you&rsquo;ve reached the green spot, usually between 1-1.5 bar, make sure the handles are fully closed by returning them to their original position.</li>
<li>Turn the boiler back on and check the pressure remains consistent. If the pressure remains steady, the issue will likely be resolved. If not you should <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a Gas Safe registered engineer</a> to investigate further.&nbsp;</li>
</ol>

How to repressurise your boiler

left

<h2>Viessmann boiler error codes</h2>
<p>Here are some of the most common Viessmann error and fault codes, and what they mean.</p>
<h3 id="h_232222911108511708094670745">Fault codes 5C, 5D, 5E and 5F</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr>
<td><strong>Boiler mode</strong></td>
<td><strong>Problem</strong></td>
</tr>
<tr>
<td>Vitotronic 300-K with Vitotronic 200 control</td>
<td>The system has gone into control mode due to a communication fault.&nbsp;</td>
</tr>
</tbody>
</table>
<h3>Fault code 10</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr>
<td><strong>Boiler mode</strong></td>
<td><strong>Problem</strong></td>
</tr>
<tr>
<td>Vitodens 200-W / 222-F / Vitotronic 300 / 200/ 200-H / 050/200-H / 300-K / vitocontrol-S</td>
<td>The outdoor temperature sensor has short-circuited - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
<tr>
<td>Vitotronic 300-K, MW2S with Vitotronic 100 / Vitodens 100-W (combiPLUS) / 200-w / Vitocontrol-S, WB2B with Vitotronic 100</td>
<td>The outdoor temperature sensor has short-circuited - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
</tbody>
</table>
<h3>Fault codes F6, 58, F9, F-E1, F-E2 and F-F6</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 39.1876px;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Boiler mode</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">All Viessman boilers</td>
<td style="height: 19.5938px;">The burner is in fault/emergency operation mode.&nbsp;</td>
</tr>
</tbody>
</table>
<h3>Fault codes 18 and D1</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 215.531px;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Boiler mode</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">Vitodens 100 / 200-W / 222-F / Vitotronic 300-K With 100 / Vitocontrol-S</td>
<td style="height: 39.1875px;">The outdoor temperature sensor is broken - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">Vitotronic / 100 / 200 / 300 / 050/200-H /300-K / Vitocontrol-S, MW1 with Vitotronic 100</td>
<td style="height: 39.1875px;">A circuit on the outdoor temperature sensor is open - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">Vitotronic 200-H / Vitotronic 300-K, MW1B with Vitotronic 300 / Vitotronic 300-K, MW2B with Vitotronic 200</td>
<td style="height: 39.1875px;">The outdoor temperature sensor is broken due to a lead break - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">Vitotronic 050/200-H</td>
<td style="height: 19.5938px;">The outdoor temperature sensor is broken - the boiler is operating as though the outdoor temperature is 32&deg;F / 0&deg;C.&nbsp;</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">Vitodens 100-W</td>
<td style="height: 19.5938px;">The burner is in fault mode, and DIP switch S2 is turned on.&nbsp;</td>
</tr>
</tbody>
</table>
<h3>Fault code A4</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr>
<td><strong>Boiler mode</strong></td>
<td><strong>Problem</strong></td>
</tr>
<tr>
<td>Vitodens 222 F</td>
<td>The burner is blocked, and the venting program is started automatically - caused by an airlock in the internal circulation pump or the minimum flow rate not being achieved.</td>
</tr>
</tbody>
</table>
<h3>Fault code OC&nbsp;</h3>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 58.7814px;"><colgroup><col style="width: 49.9465%;"><col style="width: 49.9465%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Boiler mode</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">Vitodens 100-W</td>
<td style="height: 19.5938px;">The burner is blocked due to an insufficient power supply.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">Vitodens 200</td>
<td style="height: 19.5938px;">The burner control has switched to lockout due to the flame signal still being present after switching off.&nbsp;</td>
</tr>
</tbody>
</table>
<p></p>

Need to call a Gas Safe registered engineer?

Viessmann fault & error codes

Find full lists of Worcester Bosch boiler error and fault codes with possible causes and fixes. Resolve issues with combi, system and standard boilers.

Worcester Bosch fault & error codes

Find full lists of Ideal boiler error and fault codes alongside possible causes and solutions. Keep your Ideal boiler running smoothly with help from BOXT.

<p>Noticing that there&rsquo;s a fault with your Ideal <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> is less than ideal, but getting it sorted doesn&rsquo;t have to be as much of a hassle as you&rsquo;d expect.</p>
<p>It&rsquo;s important to note that once you&rsquo;ve discovered an issue with your system, a Gas Safe registered engineer needs to be called to diagnose and rectify the problem fully.</p>
<p>To make the process of diagnosing any problems as painless as possible, Ideal pre-programs its boilers with fault and error codes. These codes are displayed on the user interface to alert you and your engineer to anything that needs attention within the system.</p>
<p>Here, we&rsquo;ll cover all of the most common Ideal boiler fault codes, discussing their meaning and advising on any next steps that you or a Gas Safe registered engineer can take to get things back to working as they should.</p>
<h2>Ideal boiler fault &amp; error codes by boiler model</h2>
<ul>
<li><a href="#h_283069789193621705408930675" rel="follow">Ideal boiler F fault codes</a></li>
<li><a href="#h_373458347195981705408940506" rel="follow">Ideal boiler L fault codes</a></li>
<li><a href="#h_651947860197021705408948577" rel="follow">Ideal boiler C fault codes</a></li>
<li><a href="#h_541516278198321705408957447" rel="follow">Additional Ideal boiler fault codes</a></li>
</ul>
<h2 id="h_283069789193621705408930675">Ideal boiler F fault codes</h2>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 293.907px;"><colgroup><col style="width: 16.4882%;"><col style="width: 40.1695%;"><col style="width: 43.3423%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Error code</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
<td style="height: 19.5938px;"><strong>Solution</strong></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F</td>
<td style="height: 19.5938px;">Boiler operating in frost mode.</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">FD</td>
<td style="height: 39.1875px;">No water flow</td>
<td style="height: 39.1875px;">Repressurise the boiler. If this doesn&rsquo;t resolve the issue, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call an engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">FU</td>
<td style="height: 19.5938px;">Flow/return differential &ndash; 50&deg;C</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F1</td>
<td style="height: 19.5938px;">Low boiler pressure</td>
<td style="height: 19.5938px;">Top up the <a href="https://www.boxt.co.uk/boilers/guides/boiler-pressure" rel="follow">water pressure</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">F2/FL</td>
<td style="height: 39.1875px;">Flame loss</td>
<td style="height: 39.1875px;">Reset the boiler. If this doesn&rsquo;t resolve the issue, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call a Gas Safe engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F3</td>
<td style="height: 19.5938px;">Fan fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F4</td>
<td style="height: 19.5938px;">Thermistor fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F5</td>
<td style="height: 19.5938px;">Return thermistor fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F6</td>
<td style="height: 19.5938px;">Outside sensor fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F7</td>
<td style="height: 19.5938px;">Low mains voltage</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F8</td>
<td style="height: 19.5938px;">Printed circuit board (PCB) fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">F9</td>
<td style="height: 19.5938px;">Unconfigured PCB.</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
</tbody>
</table>
<h2 id="h_373458347195981705408940506">Ideal boiler L fault codes</h2>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 431.063px;"><colgroup><col style="width: 16.8094%;"><col style="width: 40.0532%;"><col style="width: 43.0303%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Error code</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
<td style="height: 19.5938px;"><strong>Solution</strong></td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L1</td>
<td style="height: 39.1875px;">Low water flow</td>
<td style="height: 39.1875px;">Reset the boiler. If this doesn&rsquo;t resolve the issue, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call an engineer</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L2</td>
<td style="height: 39.1875px;">Ignition lockout</td>
<td style="height: 39.1875px;">Reset the boiler. If you hear a <a href="https://www.boxt.co.uk/boilers/guides/9-reasons-why-your-boiler-is-making-a-noise" rel="follow">rumbling noise</a>, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call an engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">L3</td>
<td style="height: 19.5938px;">No flow thermistor fault</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L9/H9/HA/LA</td>
<td style="height: 39.1875px;">Overheating</td>
<td style="height: 39.1875px;">Check pressure readings and <a href="https://www.boxt.co.uk/boilers/guides/how-to-bleed-a-radiator" rel="follow">bleed your radiators</a>. If no change, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call an engineer</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">LF</td>
<td style="height: 39.1875px;">Ignition fault</td>
<td style="height: 39.1875px;">Reset your boiler. If your boiler is rumbling, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a qualified engineer</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L4</td>
<td style="height: 39.1875px;">Flow thermistor fault</td>
<td style="height: 39.1875px;">Restart the boiler. If the issue continues, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact an engineer</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L5</td>
<td style="height: 39.1875px;">Boiler return pipe issue</td>
<td style="height: 39.1875px;">Turn off the boiler&rsquo;s power at the fuse spur, then turn it back on. If the issue persists, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">call an engineer</a>.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">L6</td>
<td style="height: 39.1875px;">Flame detection fault</td>
<td style="height: 39.1875px;">Reset your boiler. If the problem persists, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact an engineer</a>.</td>
</tr>
<tr style="height: 58.7812px;">
<td style="height: 58.7812px;">LC</td>
<td style="height: 58.7812px;">5 boiler resets in 15 minutes.</td>
<td style="height: 58.7812px;">Turn the electrical supply to the boiler off and on. If the boiler fails to operate, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a Gas Safe registered engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">L9</td>
<td style="height: 19.5938px;">Unconfigured PCB</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">L-F</td>
<td style="height: 19.5938px;">Boiler fails to ignite</td>
<td style="height: 19.5938px;">Try resetting the boiler. If nothing changes, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact an engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">L-A</td>
<td style="height: 19.5938px;">Boiler overheated</td>
<td style="height: 19.5938px;">Check that there is <a href="https://www.boxt.co.uk/boilers/guides/boiler-pressure" rel="follow">sufficient water pressure</a> in the central heating system and that all radiators have been bled. Then, reset the boiler. If the issue persists, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact an engineer</a>.</td>
</tr>
</tbody>
</table>
<h2 id="h_651947860197021705408948577">Ideal boiler C fault codes</h2>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 117.563px;"><colgroup><col style="width: 17.1306%;"><col style="width: 40.1599%;"><col style="width: 42.6025%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Error code</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
<td style="height: 19.5938px;"><strong>Solution</strong></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">C2</td>
<td style="height: 19.5938px;">Boiler chip card fault.</td>
<td style="height: 19.5938px;">Reset your boiler. If the issue persists, <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact an engineer</a>.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">C0</td>
<td style="height: 19.5938px;">Central heating signal issue.</td>
<td style="height: 19.5938px;"><a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Contact an engineer.</a></td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">C</td>
<td style="height: 19.5938px;">The boiler is operating in central heating mode. Or the boiler has a call for central heating, and the appliance has reached the desired set temperature.</td>
<td style="height: 19.5938px;">No solution needed. This is a setting, not a problem.</td>
</tr>
</tbody>
</table>
<h2 id="h_541516278198321705408957447">Additional Ideal boiler fault codes</h2>
<table border="1" style="border-collapse: collapse; width: 100.054%; height: 156.75px;"><colgroup><col style="width: 17.0236%;"><col style="width: 40.3739%;"><col style="width: 42.4955%;"></colgroup>
<tbody>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;"><strong>Error code</strong></td>
<td style="height: 19.5938px;"><strong>Problem</strong></td>
<td style="height: 19.5938px;"><strong>Solution</strong></td>
</tr>
<tr style="height: 58.7812px;">
<td style="height: 58.7812px;">D</td>
<td style="height: 58.7812px;">The boiler is operating in hot water mode, or the boiler has a call for hot water and the appliance has reached the desired set temperature.</td>
<td style="height: 58.7812px;">No solution needed; this is a setting.</td>
</tr>
<tr style="height: 39.1875px;">
<td style="height: 39.1875px;">0</td>
<td style="height: 39.1875px;">The boiler is in standby mode awaiting hot water requests or a central heating call.</td>
<td style="height: 39.1875px;">Choose your settings.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">H-3</td>
<td style="height: 19.5938px;">Domestic hot water thermistor error.</td>
<td style="height: 19.5938px;">Reset the system.</td>
</tr>
<tr style="height: 19.5938px;">
<td style="height: 19.5938px;">No display</td>
<td style="height: 19.5938px;">No heating or hot water.</td>
<td style="height: 19.5938px;">This is a PCB error. <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Call an engineer</a>.</td>
</tr>
</tbody>
</table>
<h2>Protect your home&rsquo;s central heating with BOXT</h2>
<p>Luckily, the majority of Ideal <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> problems are relatively quick and easy for qualified engineers to fix, provided they&rsquo;re identified promptly. If you suspect that any of the issues mentioned above are to blame for your boiler&rsquo;s malfunctioning, and the recommended fix isn&rsquo;t as simple as pressing the reset button, always contact a Gas Safe registered engineer who&rsquo;ll be able to come and assist you.</p>
<p>Sometimes, it&rsquo;s better to be safe than sorry. We all know that household issues arise when you&rsquo;re least prepared for them, so it helps to have a good idea of how your boiler is performing.&nbsp;</p>
<p>If you&rsquo;re unsure about the current performance of your boiler, why not book a <a href="https://www.boxt.co.uk/boilers/boiler-servicing" rel="follow">boiler service</a>? With the help of our engineers, you&rsquo;ll be sound in the knowledge that your boiler is doing the most it can possibly do for your home.</p>

Ideal boiler fault & error codes

Find full lists of Baxi boiler error and fault codes with possible causes and fixes. Resolve issues with combi, system and standard boilers.

Get in touch with our Gas Safe registered engineers today

Baxi Boiler fault & error codes

Find full lists of Vaillant boiler error and fault codes with possible causes and fixes. Resolve issues with combi, system and standard boilers.

Vaillant boiler fault & error codes

BOXT engineer arriving at the front door with his tool box

Facing Navien boiler problems? Explore these common issues, their causes, and what to do when you encounter them.

<p>Even though it&rsquo;s a relative newcomer to the UK <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> market, <a href="https://www.boxt.co.uk/boilers/navien-boilers" rel="follow">Navien</a> is one of the most trusted manufacturers there is. Across the Far East, consumers see Navien as the go-to brand for domestic home heating solutions, celebrating their industry-leading technologies, incredible energy efficiency and user-friendly features.</p>
<p>But no technology is perfect, and even the most reliable models can encounter issues from time to time. If you happen to experience a problem with your Navien boiler, getting it fixed promptly will be a top priority for everyone living in your property. Luckily, most issues can be rectified by a qualified professional pretty easily.</p>
<p>In this guide, we&rsquo;ll walk you through some of the common problems you may encounter with a Navien boiler. We&rsquo;ve split this into issues that you should be able to remedy yourself and urgent problems that should only be attempted by a Gas Safe registered engineer (such as the team at BOXT).&nbsp;</p>
<h2>Common Navien boiler problems and fixes</h2>
<p>When there's a problem with your boiler, you'll usually notice an error code or an issue with your pressure gauge being too high or too low.&nbsp;<br>Here are some of the most common Navien boiler problems and the steps you can take to fix them.</p>
<p><strong>Please note: </strong>While these fixes can be performed yourself; if you don&rsquo;t feel confident, don&rsquo;t hesitate to enlist the help of a professional.&nbsp;</p>
<h3>Ignition failure</h3>
<p>One of the most common error codes for Navien boilers is E003, which indicates there's an ignition fault.</p>
<p>If you encounter this error code, try restarting your boiler and checking the gas supply. If you've already tried those things and your boiler still fails to ignite, you should contact a Gas Safe registered engineer to determine the exact problem.</p>
<p>They'll likely need to access and inspect the boiler's controls to find the cause, whether it's debris or faulty parts.</p>
<h3>Low pressure</h3>
<p>If your pressure gauge is showing <a href="https://www.boxt.co.uk/boilers/guides/why-does-my-boiler-pressure-keep-dropping" rel="follow">little to no pressure in your boiler</a>, it likely means the water pressure in your boiler is too low for the system to work efficiently. You might also see the error code E302.</p>
<p>Low pressure can be down to numerous things, including a potential fault with the pressure relief valve or a leak within the boiler or on the system pipework.</p>
<p>If you aren't confident in attempting to raise your boiler's pressure yourself, please contact one of our expert Gas Safe registered engineers to help you.</p>
<h3>High pressure</h3>
<p>If your <a href="https://www.boxt.co.uk/boilers/guides/is-your-boiler-pressure-too-high-heres-what-to-do" rel="follow">boiler's pressure gauge is too high</a>, contact a Gas Safe registered engineer who will be able to give you expert advice.<br>For more information, see our <a href="https://www.boxt.co.uk/boilers/guides/boiler-pressure" rel="follow">complete guide to boiler pressure</a>.</p>
<p><img src="https://cdn.buttercms.com/kLpNELX3Qfy2A79LZQWJ" alt="BoilerInstall-carousel08.webp"></p>
<h2>Urgent Navien boiler problems and fixes</h2>
<p>Below are some of the most common urgent boiler problems and their potential causes. If you encounter one of these issues with your boiler, it is essential to seek an emergency boiler call out from a Gas Safe registered engineer.&nbsp;</p>
<p><strong>Important: </strong>Do <strong>NOT</strong> attempt these fixes yourself.&nbsp;</p>
<h3>Overheating heat exchanger</h3>
<p>An overheating heat exchanger (error code E016 or E046) occurs when the component responsible for transferring heat from the burner to the water becomes excessively hot.</p>
<p>This can be caused by issues such as a lack of water flow or blocked pipes. An overheating heat exchanger can lead to serious safety hazards, including potential damage to the boiler and a risk of carbon monoxide leakage, which is also <a href="https://www.boxt.co.uk/boilers/guides/carbon-monoxide-testing" rel="follow">why it&rsquo;s important to have a working carbon monoxide alarm</a>.</p>
<p>If you suspect this problem, it is crucial to <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a Gas Safe registered engineer</a> to diagnose and address the issue, ensuring both your safety and the efficiency of your boiler.</p>
<h3>Flue issue</h3>
<p>The <a href="https://www.boxt.co.uk/boilers/guides/what-is-a-boiler-flue" rel="follow">boiler flue</a> is a component that connects to your Navien boiler and safely transports the combustion gases to outside&nbsp;<br>Factors like corrosion or obstructions in the flue/exhaust pipe can cause issues, potentially leading to harmful carbon monoxide leaks within your home.</p>
<p>If you encounter any flue related problems or suspect a malfunction, or blocked condensate, it's critical to <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">contact a Gas Safe registered engineer</a> without delay.</p>
<h3>Temperature sensor issue</h3>
<p>The temperature sensors (thermistors) in your Navien boiler are responsible for monitoring and regulating the water's temperature within the appliance.</p>
<p>Issues can include general wear and tear, electrical problems, or sensor misplacement, causing the sensor to give inaccurate readings.</p>
<p>You shouldn't try to fix any underlying issue yourself. <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">Call a Gas Safe registered engineer</a>, who will replace the sensor or find the cause of the inaccurate readings for you.</p>

<h2>Choose BOXT Home Cover</h2>
<p>We know how stressful it can be when your boiler stops working. That's why, at BOXT, we offer <a href="https://www.boxt.co.uk/home-cover" rel="follow">home cover plans</a> with no call-out or excess charges as standard.</p>
<p>Our Gas Safe registered engineers are experienced in installing and maintaining <a href="https://www.boxt.co.uk/boilers/navien-boilers" rel="follow">Navien boilers</a> too, so you, and your heating, will be in safe hands.</p>
<p>For more boiler advice, whether that&rsquo;s information on <a href="https://www.boxt.co.uk/boilers/guides/what-happens-when-a-new-boiler-is-fitted" rel="follow">what happens when a new boiler is fitted</a>, <a href="https://www.boxt.co.uk/boilers/guides/clearing-an-airlock-from-your-central-heating-system" rel="follow">how to clear an airlock</a>, and <a href="https://www.boxt.co.uk/boilers/guides/full-boiler-protection-plans" rel="follow">everything you need to know about full boiler protection plans</a>, check out our <a href="https://www.boxt.co.uk/guides?category=boilers" rel="follow">dedicated boiler guides</a>.</p>
<p>If you're just after some guidance, you can message us on our&nbsp;<a href="https://www.boxt.co.uk/" rel="follow">Live Chat</a> where you get the best advice from our heating specialists.</p>

How to troubleshoot Navien boiler problems

Explore when and how to reset different models of Navien boiler, including the NCB300 and LCB700, and when you should call a Gas Safe registered technician.

<p>Whether you've had your <a href="https://www.boxt.co.uk/boilers/navien-boilers" rel="follow">Navien boiler</a> for a few years or weeks, you will likely need to reset it at some point in its lifespan.</p>
<p>To ensure the efficiency and proper maintenance of your Navien boiler, you must understand what to do when an error message appears and when to press the reset button.</p>
<p>This guide explains everything you need to know about resetting your Navien <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> and ensuring you always have heating and hot water.</p>
<h2>Where is the reset button on a Navien boiler?</h2>
<p>Typically, the reset button on a Navien boiler will be on its front panel, near the control display.&nbsp;</p>
<p>The reset button's precise position on your boiler unit will vary based on the Navien model you own, so it's a good idea to check the instruction manual for the exact location.</p>
<h2>When to reset a Navien boiler</h2>
<p>Occasionally, your boiler may experience faults that require you to press the reset button. If there's a problem with your boiler, like a faulty heat exchanger or water heater, it can shut down completely, known as a 'lockout'.</p>
<p>A boiler will perform a lockout to preserve your safety and avoid a more severe fault occurring. When this happens, you should perform a system reset. Additionally, you may have to reset your boiler if there's a problem with the power supply or a power cut.</p>
<p>You should be aware that resetting your Navien boiler may not fix the issue, and you may need to contact technical support or a Gas Safe registered engineer to investigate the problem further. Where this is the case, the control panel or screen may show an error message or code you can look up in your Navien boiler's instructions.</p>
<p>As with all machines, a mechanical or electrical fault can occur at any time, so it's essential you&nbsp;<a href="https://www.boxt.co.uk/home-cover" rel="follow">get your boiler serviced</a> regularly.</p>

Choose BOXT Home Cover to protect your boiler

<h2>Can you reset a Navien boiler yourself?</h2>
<p><a href="https://www.boxt.co.uk/boilers/guides/boiler-not-firing-up" rel="follow">Resetting your boiler</a> is a straightforward process, so if you feel confident doing it, you can save time and money by doing it yourself. Before you do, read your boiler's manual. You must also wait before pressing the reset button again, as pressing it multiple times in quick succession could cause further problems.</p>
<h2>How to reset a Navien boiler</h2>
<p>Specific reset processes will vary based on the model of the Navien boiler you own. To help you, we've outlined the steps to resetting different Navien models below.</p>
<h3>NCB300</h3>
<p>To reset a Navien NCB300, press the Power button. If this doesn't work, refer to the troubleshooting section of the instruction manual.</p>
<h3>LCB700, NCB700 &amp; NCB500</h3>
<p>Press the Back button to reset an NCB500 boiler. If this doesn't work, contact Navien tech support or consult the manual's troubleshooting section.</p>
<h3>NCB-24LDWE</h3>
<p>Press the Reset button on the system's front panel if an error code appears.</p>
<h2>What happens after you reset your Navien boiler?</h2>
<p>Depending on the extent of the problem, your Navien boiler will either show an error code on its panel display or resolve the issue automatically and get straight back to working as expected.</p>
<p>If your <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> reset has gone to plan, the boiler will fire up as expected, and any error messages will disappear. The reset procedure can take a couple of minutes, so avoid pressing the reset button multiple times - this can cause further complications.</p>
<h2>When to call a professional</h2>
<p>If you press the reset button and the error code persists, contact a trained professional for <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">boiler repairs</a>. You should report any problems quickly so an engineer can fix them before they worsen.</p>
<p>For more <a href="https://www.boxt.co.uk/guides?tag=boiler-maintenance" rel="follow">boiler maintenance</a> advice, check out our blog's dedicated section. Here, you'll find tips and information on everything, from <a href="https://www.boxt.co.uk/boilers/guides/clearing-an-airlock-from-your-central-heating-system" rel="follow">how to clear an airlock</a> to <a href="https://www.boxt.co.uk/boilers/guides/how-to-clean-magnetic-filter-on-boiler" rel="follow">how to clean a magnetic filter</a> and more.</p>

How to reset a Navien boiler

In this guide, we’ll walk you through everything you need to know about your boiler’s condensate pipe, cutting through the jargon so you can feel confident about the inner-workings of your home’s central heating system.

<p>If you&rsquo;re stuck when it comes to knowing your flues from your thermostats and your <a href="https://www.boxt.co.uk/boilers/combi-boilers" rel="follow">combi boilers</a> from your condensing, you&rsquo;re definitely not on your own. Knowing how to identify every pipe, button, and outlet that's attached to your boiler can be tricky.</p>
<p>A repeat offender when it comes to confusing homeowners is condensate pipes. What are they? What do they do? And why are they important?</p>
<p>In this guide, we&rsquo;ll walk you through everything you need to know about your <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a>&rsquo;s condensate pipe, cutting through the jargon so you can feel confident about the inner workings of your home&rsquo;s central heating system.</p>
<h2>Firstly, what is a condensing boiler?</h2>
<p>Before we take a closer look at condensate pipes, we first need to understand what condensing boilers are.&nbsp;</p>
<p><a href="https://www.boxt.co.uk/boilers/guides/what-is-a-condensing-boiler">Condensing boilers</a> are a highly efficient type of home heating system. They are designed to maximise the heating potential of the energy they burn by minimising the amount that&rsquo;s lost when generated as a byproduct. The result? Condensing boilers are able to give you more hot water per penny spent, improving your home&rsquo;s energy efficiency and helping to reduce your carbon footprint in the process.</p>
<p>To do this, condensing boilers capture the products of combustion (fumes) that are generated through the combustion of natural gas, LPG, or oil (depending on the boiler&rsquo;s fuel type) via the heat exchanger. On condensing boilers, these heat exchanges extract more heat from the products of combustion due to their design. So much so that the gases turn, or &lsquo;condensate&rsquo;, back into liquid form. This condensate water is mildly acidic.&nbsp; Condensing appliances can produce up to 3 litres per hour. All of this water has to be collected and removed from the boiler&rsquo;s system, and this is where condensate pipes come in.&nbsp;</p>
<h2>What does a condensate pipe do?</h2>
<p>The condensate pipe is an outlet, usually made from plastic or PVC, that transports acidic wastewater (condensate) from your boiler to drains located outside your home.<br><br>When it&rsquo;s fired up and running, your boiler can generate an impressive 2-3 litres of condensate waste per hour, all of which need to be removed from the system to keep everything operating smoothly and safely.&nbsp;</p>
<p>The condensate pipe is designed to release water once the volume hits a certain threshold and is usually released in around 300ml increments. This is to reduce the risk of the water freezing in the part of the pipe that's outside your home, which could then cause a blockage.</p>
<p>The condensate pipe will usually come out of the back of your boiler, down the external wall, and into the drain. It could also terminate into a waste pipe internally (a sink waste pipe, for example). It's a small, usually-white pipe, so It should be easy to spot amongst the metal pipes.</p>
<h2>What happens if a boiler&rsquo;s condensate becomes blocked?</h2>
<p>Over time, sediment can start to build up in your condensate sump pump and/or pipe. The U bend or syphon-shaped 'trap' part of your condensate pipe, which is responsible for safely collecting and releasing the wastewater, is usually where the sediment will sit. Build-up can come from things like tiny bits of the heat exchanger if it's corroded, which can ultimately end up in your condensate trap.<br><br>If there is enough sediment build-up, condensate wastewater will cease to flow, causing the liquid to back up into the bottom of the heat exchanger. Your boiler will then automatically stop working for safety reasons. &nbsp; <br><br>You shouldn't have to worry too much about this happening if your boiler is regularly serviced. Your heating engineer will clear the condensate trap during your service. Cogged condensate pipe traps are usually only to be expected in appliances that haven't been serviced in a long time.</p>
<p>Telltale signs that your condensate pipe has a blockage include the boiler making a gurgling sound when it&rsquo;s fired up due to wastewater struggling to pass through the pipework and, if the blockage is bad enough, the boiler stopping working altogether.</p>
<p>If you suspect a clogged condensate pipe trap is to blame for your boiler failing, you should contact an engineer rather than trying to fix the problem yourself, as the job requires a <a href="https://www.boxt.co.uk/home-cover">Gas Safe registered expert</a>. Your engineer will clean the trap by removing it and rinsing it out thoroughly before refilling and refitting it.<br><br>If you'd like us to come and take a look, you can <a href="https://www.boxt.co.uk/boilers/boiler-repair">book a boiler repair here</a> by answering a few simple questions about your home and boiler.</p>
<h2>Need a new condensate pipe or condensing boiler?</h2>
<p>Since the legislation was introduced way back in 2005, all new boiler installations must be condensing boilers. This is because condensing boilers are far more efficient than old-style non-condensing boilers, reaching energy efficiencies of above 90%.</p>
<p>At BOXT, we supply a huge range of A-rated condensing boilers from brands such as Ideal, Baxi, Navien and Worcester Bosch with industry-leading home cover <a href="https://www.boxt.co.uk/boilers/boiler-servicing" rel="follow">boiler service</a> plans to keep things running smoothly.</p>

Boiler condensate pipes - What are they and what do they do?

If you can hear strange kettling noises coming from your boiler, take a look at this handy BOXT guide to determine the possible causes and how to fix them. 

<p>Do you have a strange noise coming from your boiler? If so, your boiler might be experiencing what is known as &lsquo;boiler kettling&rsquo;.</p>
<p>We've already covered <a href="https://www.boxt.co.uk/boilers/guides/9-reasons-why-your-boiler-is-making-a-noise" rel="follow">boiler noises</a> in another blog, but we're going to cover kettling in more detail.</p>
<p>So what is boiler kettling, what causes <a href="https://www.boxt.co.uk/boilers" rel="follow">boilers</a> to kettle, and what can you do to fix it? We're going to walk you through everything you need to know.</p>
<h2>What exactly is boiler kettling?</h2>
<p>Before determining the cause of the boiler kettling sounds, it's a good idea to know what boiler kettling actually is. Boiler kettling is a whistling, bubbling or popping noise that comes from your boiler while it's running.</p>
<p>The hot water inside a boiler should not boil. But if something was to cause the water flow inside the system to slow down, there&rsquo;s a chance that the water could well boil. This is when the boiler kettling noise occurs - just like a boiling kettle.</p>
<p>Before coming up with a solution, you'll need to know what's causing this boiler kettling noise.</p>
<h2>Common causes of boiler kettling</h2>
<p>There are three likely causes of boiler kettling: overheating, limescale buildup or a leak. We'll walk you through how to identify the cause of your boiler noise and what can be done to fix the problem.</p>
<h3>Cause 1: Overheating</h3>
<p>If your boiler keeps cutting out and making strange kettling noises, a likely cause is overheating. Often, an overheating boiler is down to a faulty thermostat. If you have a faulty thermostat, take a look at our other guide on <a href="https://www.boxt.co.uk/boilers/guides/thermostat-not-working" rel="follow">why your thermostat may not be working</a> to help find the solution.</p>
<p>Overheating can also be caused by blocked/partially blocked pipework that can happen over time, depending on the age of the system. If you have a blockage, then you potentially would need the system looking at, and a powerflush may be required to remove and clear the blockage.</p>
<p>The kettling noise occurs when a boiler is overheating because the inside of the heating system is getting too hot. The hot water in the boiler system turns into steam, creating the strange kettling noise you can hear coming from your boiler.</p>
<h3>Cause 2: Limescale buildup</h3>
<p>Another reason for boiler kettling could be limescale buildup. No boiler is immune from limescale buildup. But even though it is a natural occurrence, it does need to be dealt with.</p>
<p>If the limescale begins to cause a blockage, the heat and water will only have so much space to move around, which can cause your boiler to make a kettling noise.</p>
<p>Limescale buildup can also cause blockages in the system to the extent that some radiators or appliances aren't working as well as they once did.</p>
<p>Thankfully this isn't a safety issue, but it will need flushing to release any buildup.</p>
<p>If you live in a hard water area, you're much more likely to have limescale buildup in your heating system, as hard water contains more minerals.</p>
<h3>Cause 3: A leak</h3>
<p>A <a href="https://www.boxt.co.uk/boilers/guides/is-a-leaking-boiler-an-emergency" rel="follow">boiler leak</a> can also cause kettling, as the system will try to balance the water flow and pressure. If you think this could be the case for your boiler, you'll need to check for leaks. The leak could be close to the boiler unit or anywhere throughout the pipework.</p>
<p>Your central heating system could be leaking for several reasons, from poorly installed pipework to general corrosion.</p>
<h2>How to fix a kettling boiler</h2>
<p>The right solution for the boiler kettling will depend on what is causing the noise to occur in the first place. If you've read the list of causes above and think you've figured out what might be causing your boiler to make strange kettling sounds, read on to find out what can be done to stop your boiler from kettling.</p>
<h3>Solution 1: How to fix an overheating boiler</h3>
<p>If you think the cause of your boiler kettling might be overheating, check the settings on your thermostat. If you're confident enough, adjust or reset the thermostat to bring your boiler back to a suitable temperature.</p>
<p>The safest option would be to call a heating engineer to find a solution. If your thermostat is broken, you will need a <a href="https://www.boxt.co.uk/boilers/boiler-repair" rel="follow">boiler repair</a> or replacement.</p>
<h3>Solution 2: How to remove limescale buildup in a boiler</h3>
<p>If the boiler kettling noise is a result of limescale buildup, you'll need to get in touch with a heating engineer. They can perform a system flush to clear your system of debris or limescale.</p>
<p>A chemical flush uses high-strength chemicals to corrode the debris, whereas a power flush uses pressurised water to do the same.</p>
<p>If the boiler kettling noise doesn't stop, there will be a different cause elsewhere in the system.</p>
<h3>Solution 3: How to fix a boiler leak</h3>
<p>If you suspect a boiler leak, you'll need a Gas Safe registered engineer to solve the problem. If you attempt to solve the problem yourself, not only could you be putting yourself in danger, but you could also invalidate your boiler warranty or guarantee.</p>
<p>The heating engineer will be able to inspect the entire central heating system and pipework for any potential leaks causing the boiler kettling.</p>

<h2>Is boiler kettling dangerous?</h2>
<p>Boiler kettling doesn't usually indicate immediate danger, but finding a solution as quickly as possible is wise. The high pressure in the boiler could eventually burst internal pipework. However, modern boilers have built-in safeguard features to shut down the boiler before it reaches this point.</p>
<p>Waiting to fix a problem with your <a href="https://www.boxt.co.uk/boilers" rel="follow">boiler</a> could lead to a much bigger issue later down the line, which could be much more costly. If you notice that your boiler is making a kettling noise or not working as well as it once did, it's best to get in touch with a Gas Safe registered engineer for a <a href="https://www.boxt.co.uk/boilers/boiler-servicing" rel="follow">boiler service</a> as soon as possible.</p>

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