Head to head
Worcester Bosch Greenstar 4000 25kW combi vs Worcester Bosch Greenstar 8000 Life 40kW combi
The Worcester Bosch Greenstar 8000 Life 40kW combi has 15kW more hot water output and puts out 15kW more to the radiators.
Last reviewed 13 September 2026
Key differences
- Hot water output: the Worcester Bosch Greenstar 8000 Life 40kW combi has 15kW more hot water output.
- Central heating output: the Worcester Bosch Greenstar 8000 Life 40kW combi puts out 15kW more to the radiators.
- Hot water flow rate: the Worcester Bosch Greenstar 8000 Life 40kW combi runs 3.8 litres a minute more hot water.
- Warranty: the Worcester Bosch Greenstar 8000 Life 40kW combi comes with 2 years more warranty.
Specifications side by side
| Worcester Bosch Greenstar 4000 25kW combi | Worcester Bosch Greenstar 8000 Life 40kW combi | |
|---|---|---|
| Hot water output | 25 kW | 40 kW |
| Central heating output | 25 kW | 40 kW |
| ErP class | A | A |
| Seasonal efficiency | 94% | 94% |
| Dimensions | 710 x 400 x 310 mm | 780 x 440 x 365 mm |
| Warranty | 10 years | 12 years when installed by a Worcester Bosch accredited installer |
| Hot water flow rate | 10.5 litres per minute | 14.3 litres per minute |
| Weight | 32.0 kg | - |
Sources: Worcester Bosch Greenstar 4000 25kW combi, Worcester Bosch Greenstar 8000 Life 40kW combi. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the Greenstar 4000 25kW combi if...
A gas combi boiler with 25 kW of hot water output, sized for a flat or small house with one bathroom. It delivers about 10.5 litres per minute of hot water, which decides how well a shower runs while a tap is on. Warranty: 10 years. Seasonal efficiency is 94%.
Full Greenstar 4000 25kW combi specifications →Buy or hire the Greenstar 8000 Life 40kW combi if...
- you want one that has 15kW more hot water output
- you want one that puts out 15kW more to the radiators
- you want one that runs 3.8 litres a minute more hot water
- you want one that comes with 2 years more warranty
A gas combi boiler with 40 kW of hot water output, sized for a larger house with two bathrooms. It delivers about 14.3 litres per minute of hot water, which decides how well a shower runs while a tap is on. Warranty: 12 years when installed by a Worcester Bosch accredited installer. Seasonal efficiency is 94%.
Full Greenstar 8000 Life 40kW combi specifications →Common questions
What is the difference between the Worcester Bosch Greenstar 4000 25kW combi and the Worcester Bosch Greenstar 8000 Life 40kW combi?
The Worcester Bosch Greenstar 8000 Life 40kW combi has 15kW more hot water output and puts out 15kW more to the radiators. The Worcester Bosch Greenstar 4000 25kW combi is a gas combi boiler, 25 kW hot water output; the Worcester Bosch Greenstar 8000 Life 40kW combi is a gas combi boiler, 40 kW hot water output.
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