Greenstar 4000 30kW Combi
Worcester Bosch's accessibly-priced combi for a typical UK 3-bed. The reason it remains the default is not that it is the most efficient unit on the market but that almost every gas engineer in Britain has fitted one, and the parts arrive next day.
- ErP
- A-rated
- Running cost
- £1,120/yr
- Installed
- £2,400 to £2,900 installed
Editorial render. Not a manufacturer photograph; we do not redistribute press imagery without a licence.
Primary question · If I need a new boiler now, is the Worcester still the safe default?
Anyone replacing a failed boiler tomorrow who values service-network depth over headline efficiency.
£2,400 to £2,900 installed
- Universally serviceable
- Long, transparent warranty
- Quiet for its class
- Premium pricing for what is, in 2026, a mature technology
- Controls UX has dated against Vaillant
Open the cost planner to estimate your installed price.
Key specifications
- Output
- 30 kW heating, 30 kW hot water
- ErP
- A-rated
- Hot water flow
- 12.3 L/min at 35°C rise
- Warranty
- 8 years (registered installer)
- , Universally serviceable
- , Long, transparent warranty
- , Quiet for its class
- , Premium pricing for what is, in 2026, a mature technology
- , Controls UX has dated against Vaillant
If your brief matches "anyone replacing a failed boiler tomorrow who values service-network depth over headline efficiency.", the Greenstar 4000 30kW Combi is a confident pick. If it doesn't, the alternatives above are more honest answers.
Estimate your installed cost
The planner uses your specific home; not a brochure number.