Worcester Greenstar 4000 25kW Combi Boiler
Upgrade your home heating with the Worcester Bosch Greenstar 4000 25kW combi boiler. Built for medium-sized homes, this boiler combines high efficiency with powerful performance, giving you reliable hot water and heating while helping to reduce energy costs.
- Heat output: 25kW
- 20% Hydrogen-mix Ready
- Aluminium Silicon Heat Exchanger
Worcester Bosch Greenstar 4000 25kW Combi Boiler
The Worcester Bosch Greenstar 4000 25kW combi boiler is one of the most popular choices for UK homes, combining 94% efficiency, reliable performance, and a sleek, compact design. Perfect for small to medium-sized properties, this wall-mounted gas and LPG condensing boiler delivers excellent hot water flow and low running costs—making it one of Worcester Bosch’s premium models.
Key Benefits
Compact size – easily fits into a kitchen cupboard or utility space
High efficiency – 94% / A-rated for lower energy bills
Flexible heating power – 1:10 modulation for maximum efficiency
Future-ready – compatible with a 20% hydrogen blend
Peace of mind – up to 10-year Worcester Bosch warranty
Powerful performance – capable of heating larger homes with two bathrooms
Smart controls – works seamlessly with Bosch EasyControl
Quiet operation – so discreet it doesn’t need to be hidden away
Technical Details
Output: 25kW Gas & LPG condensing boiler (LPG version available)
Dimensions: 724mm (H) x 400mm (W) x 310mm (D)
Control system: User-friendly LCD screen with push-button operation
Environmentally Friendly Heating
The Worcester Bosch Greenstar 4000 is designed with sustainability in mind. With low CO2 emissions and hydrogen-ready technology, this boiler helps reduce environmental impact while keeping your home warm and efficient.
🔥 Why choose The Boiler Team?
We offer expert installation, competitive prices, and extended warranties on Worcester Bosch boilers, giving you complete confidence in your home heating.
Boiler Specifications
| Manufacturer | Worcester Bosch |
| Model | GREENSTAR 4000 25kW |
| Condensing | Yes |
| Efficiency Rating | 94% |
| Energy Efficiency Class | A Rated |
| Modulation Range | 1:8 |
| LPG Version | Yes |
| Warranty | Up to 10-year comprehensive warranty |
| Hot Water Output | 25kW |
| Combi Hot Water Flow Rate | 10.2 litres/minute |
| Central Heating Output – 50/30 °C | 3.1-25kW |
| Mounting | Wall Mounted |
| Colour | White |
| Weight | 35kg |
| Dimensions – Height | 724mm |
| Dimensions – Width | 400mm |
| Dimensions – Depth | 310mm |
Boiler Team Review
The Worcester Bosch Greenstar 4000 25kW combi boiler is a top choice for UK homes, offering 94% efficiency, quiet operation, and compact design. Perfect for kitchens, cupboards, or utility spaces, it delivers reliable heating and hot water for small to medium homes—even with two bathrooms.
With user-friendly LCD controls and compatibility with smart thermostats like Bosch EasyControl, Nest, and Hive, managing your heating has never been easier. Its hydrogen-ready technology and low CO2 emissions make it an environmentally conscious choice, while a 10-year warranty gives peace of mind.
Engineered for easy installation and servicing, the Greenstar 4000 is a durable, efficient, and future-ready boiler.
Boiler Team Verdict: Efficient, reliable, and compact—a smart investment for your home heating needs.
Fast & Reliable Boiler Installation UK
Looking for professional boiler installation in the UK? The Boiler Team makes it simple—get an instant online quote in under 1 minute and see your price immediately.
Why choose The Boiler Team for boiler installation UK:
-
All-inclusive pricing: Flushing, filters, labour, VAT—everything covered for efficiency and longevity.
-
Manufacturer-trained installers: Full warranty protection on every UK boiler installation.
-
Next-day installation: Quick and hassle-free service for boilers and central heating systems.
-
Trusted by homeowners: Rated 5★ Excellent on Google.
-
Flexible finance options: Spread the cost with tailored plans.
-
Long-term peace of mind: 10–12 year warranties and ongoing manufacturer support.
-
Compare multiple quotes: Up to three options to find the perfect boiler.
We don’t just install your boiler—we support it for life. From ensuring full warranty compliance to arranging annual servicing, The Boiler Team keeps your system running safely and efficiently across the UK.
Get your instant, no-obligation quote today for reliable boiler installation UK and join thousands of satisfied homeowners.
Worcester Bosch boiler installation UK – efficient, reliable heating for your home.
Frequently Asked Questions About Worcester Bosch
Find answers about Worcester Bosch boilers, including combi, system, and conventional models for gas or oil. Get the key info you need to choose the right boiler for your home.
- Central Heating (CH) Output: 24kW
- Domestic Hot Water (DHW) Output: 25kW
It includes a standard 7-year warranty, which can be extended to 8 years when installed with a Worcester filter.
Yes, the boiler is compatible with smart thermostats, including Worcester Bosch's EasyControl and third-party options like Google Nest, allowing for remote management
It features an Intelligent Filling System that automatically maintains optimal system pressure, notifying users if manual intervention is needed
Yes, this model is capable of running on a 20% hydrogen blend, making it future-proof for evolving energy standards.
While the Greenstar 4000 offers excellent efficiency and reliability, some competitors, like Viessmann, use stainless steel heat exchangers and brass components, which may offer longer-term durability.
Boiler Finance Available
Spread the cost of your new boiler.
