Worcester Bosch Greenstar 4000

Answer a few quick questions about your home to get a fixed price for a Worcester 4000 with finance available.

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Supplied & installed from £2,199

Installed as soon as the next working day*

We'll beat any like-for-like price

What makes the Worcester Bosch Greenstar 4000 so good?

Our best selling boiler, and for good reason. The Greenstar 4000 comes in a range of outputs so it can efficiently power different sized homes, and has a modern design and digital display to seamlessly fit into your home.

10 year warranty
BOXT's best selling boiler
Available in 12-30kwh
Available in combi and system
Available in gas or LPG
A rated efficiency

Included as standard with your Worcester Bosch 4000 installation from BOXT

All installation and labour costs included in your fixed price, so the price you see is what you'll pay

10 year manufacturer-backed warranty, that we register for you

12 month workmanship guarantee, covering all work carried out by our engineer for a full year after installation

System flush, to ensure your heating system is in the best health possible for your new Worcester boiler

Magnetic filter, to keep your new Worcester boiler healthy and efficient for longer

Carbon monoxide alarm, helping to keep you and your family safe

Wireless thermostat, to easily control your heating on a schedule that works for your home

Get the Worcester 4000 on an all-inclusive plan

Get your new Worcester 4000 installed, plus annual servicing and unlimited repairs for a fixed price from only £33.35 a month. When you choose our stress-free, all-inclusive BOXT life boiler plan, you benefit from:

- A new A-rated boiler installed

- Annual services for 10 years

- No callout fees

- Unlimited boiler repairs for 10 years

- Fix or replace

- No deposit or price rises

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BOXT customer reviews of the Worcester Bosch Greenstar 4000

Great service. Wouldn’t hesitate to recommend BOXT. I was given a price to fit a Worcester Greenstar 4000 30Kw LPG boiler in my 2 bedroomed, one shower, Park Home. The price included EVERYTHING needed to get my new boiler fitted and up and running.

Ellie

BOXT were able to fit my boiler within days. Even better, the final price was cheaper than the well known competitor and for a higher spec boiler too (greenstar 4000 from BOXT vs greenstar 2000 from competitor). I’m absolutely chuffed to bits!

Natalie M

I'm a British Gas customer but chose BOXT for my 20-year-old boiler replacement as they quoted me almost half the price. I selected the Worcester Bosch Greenstar 4000 30kW. I am a very happy customer and will shop again. Highly recommended

Amer Butt

I needed a new combi boiler so decided to go with the Worcester bosch 4000 30kw, I've no regrets as it performs far better than my previous combi. The whole process ran smoothly.

Jamie Thomson

The Worcester Bosch Greenstar 4000 boiler has been flawless in performance, bringing noticeable improvements in heating and efficiency. On top of that, the price was unbeatable —around £1,000 cheaper than the closest quote I received.

Cal Whyte

I had a Worcester Bosch 4000 installed to replace a 10-year old boiler. I was happy with the price (less than I paid for the last one!) and it was very easy to book. I chose a date two weeks off and saved £200 in the process.

Steve Cribbin

The boiler itself is great (Worcester Bosch Greenstar 4000) it's my first Combi Boiler. An unexpected plus point is that I no longer need a shower pump so it's less noisy now. So happy with the price, service, equipment and the fitter.

David Birkett

A couple of weeks ago I had a Worcester Greenstar 4000 25kW Combi boiler fitted from BOXT. I have waited to see how the boiler performed and to my delight its got 5 stars so far.

John Campbell

Reliability: 5/5

Worcester Bosch is known for its reliable boilers, backed by a 10 year guarantee. The Greenstar 4000’s removable side panels allow easy maintenance, saving time and money. With an Excellent rating (4.6/5 from 40,000+ reviews) and 14 consecutive Which? Best Buy awards, it’s widely regarded as the most reliable boiler brand.

Efficiency: 5/5

The Greenstar 4000 has an A-rated 94% efficiency, meaning only 6% of energy is wasted — just 6p lost for every £1 spent on heating. Its Quick Tap feature reduces water waste, while modulating technology lowers output to 10% when demand is low, saving both energy and money.

Performance: 5/5

Features an optional intelligent filling valve that maintains optimal pressure and alerts you to pressure loss. Strong flow rates of 10.5L/min for the 25kW model and 12.3L/min for the 30kW, making it ideal for homes with one or more bathrooms. Designed to prevent frozen condensate pipes and operating at just 45 decibels, it’s one of the quietest boilers available.

Cost: 4.5/5

While Worcester Bosch boilers come at a premium, their quality and reliability justify the cost. Choosing the right boiler depends on your home’s needs, not just price. With BOXT, you can get a Greenstar 4000 installed as soon as the next day, with extras like a wireless thermostat, magnetic filter, and a full system flush included in the price.

BOXT's video review of the Greenstar 4000

Check if the Worcester Bosch Greenstar 4000 is right for your home

^*Next working day installation when you order before 3pm, subject to availability.

All prices are correct as of October, 2025.

BOXT Limited is authorised and regulated by the Financial Conduct Authority. FCA register No. 767308. Finance is offered through HomeServe Finance Limited (FRN 994955) and in some cases we also lend with Propensio Finance Limited (FRN 806409). Finance available subject to status, affordability and a credit check. Terms and conditions apply. BOXT Limited acts as a credit broker and is not a lender. Registered in England & Wales company No. 08086606 VAT No. 257059782. BOXT Limited, 3320 Century Way, Thorpe Park, Leeds, West Yorkshire, LS15 8ZB.