Head to head
Worcester Bosch Greenstar 2000 25kW combi vs Worcester Bosch Greenstar 4000 30kW combi
The Worcester Bosch Greenstar 4000 30kW combi comes with 3 years more warranty and runs 2.3 litres a minute more hot water.
Last reviewed 13 September 2026
Key differences
- Warranty: the Worcester Bosch Greenstar 4000 30kW combi comes with 3 years more warranty.
- Hot water flow rate: the Worcester Bosch Greenstar 4000 30kW combi runs 2.3 litres a minute more hot water.
- Hot water output: the Worcester Bosch Greenstar 4000 30kW combi has 5kW more hot water output.
Specifications side by side
| Worcester Bosch Greenstar 2000 25kW combi | Worcester Bosch Greenstar 4000 30kW combi | |
|---|---|---|
| Hot water output | 25 kW | 30 kW |
| Central heating output | 3-24 kW | 30 kW |
| ErP class | A | A |
| Seasonal efficiency | 94% | 94% |
| Dimensions | 724 x 400 x 300 mm | 710 x 400 x 310 mm |
| Weight | 32.1 kg | 32.3 kg |
| Warranty | 7 years when installed with Greenstar System Filter | 10 years |
| Hot water flow rate | 10 litres per minute at 35 C rise | 12.3 litres per minute |
Sources: Worcester Bosch Greenstar 2000 25kW combi, Worcester Bosch Greenstar 4000 30kW combi. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the Greenstar 2000 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 litres per minute at 35 C rise of hot water, which decides how well a shower runs while a tap is on. Warranty: 7 years when installed with Greenstar System Filter. Seasonal efficiency is 94%.
Full Greenstar 2000 25kW combi specifications →Buy or hire the Greenstar 4000 30kW combi if...
- you want one that comes with 3 years more warranty
- you want one that runs 2.3 litres a minute more hot water
- you want one that has 5kW more hot water output
A gas combi boiler with 30 kW of hot water output, sized for a three-bed house with one or two bathrooms. It delivers about 12.3 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 30kW combi specifications →Common questions
What is the difference between the Worcester Bosch Greenstar 2000 25kW combi and the Worcester Bosch Greenstar 4000 30kW combi?
The Worcester Bosch Greenstar 4000 30kW combi comes with 3 years more warranty and runs 2.3 litres a minute more hot water. The Worcester Bosch Greenstar 2000 25kW combi is a gas combi boiler, 25 kW hot water output; the Worcester Bosch Greenstar 4000 30kW combi is a gas combi boiler, 30 kW hot water output.
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