The Worcester Bosch Greenstar 4000 30kW Combi heats your radiators and gives you hot water straight from the mains, with no tank or cylinder. It’s the bigger hot water version of the Greenstar 4000, so it’s a good fit if you want stronger showers. You can see your fixed installed price online in a couple of minutes.
Key specs
| Spec | Worcester Bosch Greenstar 4000 30kW Combi |
|---|---|
| Boiler type | Combi, condensing, wall mounted |
| Fuel | Mains gas |
| Central heating output | 3 to 24 kW |
| Hot water output | 30 kW |
| Hot water flow rate | 12.3 l/min (35°C rise), 10.8 l/min (40°C rise) |
| Minimum mains pressure for full flow | 1.2 bar |
| Modulation | 1:10 |
| Efficiency | 94%, A-rated (ErP: A heating, A hot water) |
| Size (H x W x D) | 724 x 400 x 310 mm |
| Weight | 32.3 kg |
Specs are from Worcester Bosch’s Greenstar 4000 technical data.
Greenstar 4000 30kW price, fitted
Our new boilers start from £1,790 supplied and fitted. Your price for the Greenstar 4000 30kW depends on your home and what’s being swapped, and you’ll see it fixed before you pay. Every install includes:
- The Greenstar 4000 30kW Combi, fitted by a Gas Safe registered engineer
- A thermostat
- Removal of your old boiler
- A guarantee of up to 14 years depending on model, registered with Worcester Bosch for you
Who it suits
- Small to medium homes that want a stronger shower than the 25kW gives.
- Homes with one bathroom, or a bathroom and an en suite, where only one tap runs at a time.
- Homes with mains pressure of at least 1.2 bar.
- If you only need a basic swap in a flat or small house, the Greenstar 4000 25kW may be enough.
Greenstar 4000 30kW review: why people choose it
- More hot water: 12.3 l/min, against 10.2 l/min on the 25kW.
- Wide modulation: Turns down to 3 kW of heating (1:10), so it doesn’t waste gas on mild days.
- Quiet: Worcester Bosch markets it as one of its quietest combis, and it’s Quiet Mark certified.
- QuickTap: A water saving mode, handy if you’re on a water meter.
- Easy to use: A clear colour display, and it works with Bosch EasyControl.
- Fits a cupboard: 400mm wide with 5mm side clearance.
Want to compare other models? See the full Worcester Bosch range.
Next day installation
Order by 3pm and we can fit your boiler the next day, 7 days a week. Installs are often available the same week. There’s no survey. You upload a few photos of your boiler and pipework, and we fix your price from those. Swapping a system or regular boiler for a combi takes 2 days. More about next day boiler installation.
We fit boilers across England, Scotland and Wales. We don’t cover Northern Ireland.
Spread the cost with Zopa
- No deposit and no minimum spend
- 0% interest over up to 3 years
- 4 to 10 years at 10.9% APR representative
- Soft credit search, so applying won’t affect your credit score
- First payment 20 to 30 days after your boiler is fitted
- No early repayment fees
Finance is through Zopa and subject to status. See boiler finance for more.
Protect it with boiler cover
You can add a cover plan. Your annual service is included after 10 payments.
FAQs
Is the Greenstar 4000 30kW big enough for my home?
It suits small to medium homes, typically with one bathroom or a bathroom and an en suite. Our online questions check your home and recommend the right size before you see a price.
What’s the difference between the Greenstar 4000 25kW and 30kW?
Both give up to 24 kW to your radiators. The 30kW gives more hot water: 12.3 l/min against 10.2 l/min on the 25kW (35°C rise). If you want stronger showers, the 30kW is the better pick.
What flow rate does the Greenstar 4000 30kW give?
12.3 litres a minute at a 35°C rise and 10.8 litres a minute at a 40°C rise, according to Worcester Bosch. It needs at least 1.2 bar mains pressure to reach full flow.
How efficient is it?
It’s ErP A-rated for heating (94%) and A-rated for hot water.
Will it fit in my kitchen cupboard?
It measures 724mm high, 400mm wide and 310mm deep, and needs only 5mm clearance at the sides, so it fits most standard kitchen cupboards. Your photos let us check the space.
What guarantee does it come with?
It comes with a guarantee of up to 14 years depending on model, and we register it with Worcester Bosch for you.
Do you need to visit before fitting it?
No. You answer a few questions and upload photos of your current boiler. There’s no home survey.
How fast can you fit it?
Order by 3pm for next day installation, 7 days a week. Installs are often available the same week. If you’re converting from a system or regular boiler to a combi, the job takes 2 days.
Can I spread the cost?
Yes. Zopa finance has no deposit, 0% over up to 3 years, or 4 to 10 years at 10.9% APR representative, with a soft credit search.
Get your fixed price online
Answer a few quick questions about your home and current boiler. You’ll see a fixed installed price straight away and can book online.