Head to head
Joule Cyclone Air 150L Direct vs Worcester Bosch Greenstar 4000 30kW combi
The Worcester Bosch Greenstar 4000 30kW combi comes with 9 years more warranty.
Last reviewed 13 September 2026
Key differences
- Warranty: the Worcester Bosch Greenstar 4000 30kW combi comes with 9 years more warranty.
Specifications side by side
| Joule Cyclone Air 150L Direct | Worcester Bosch Greenstar 4000 30kW combi | |
|---|---|---|
| Dimensions | 1196 x 540 x 540 mm (H x W x D) | 710 x 400 x 310 mm |
| Warranty | 1 year manufacturer's warranty | 10 years |
| Capacity | 150 litres | - |
| Heat-up time | 57 minutes (full tank, 6kW immersion) | - |
| Immersion heater | 6kW (2 x 3kW) | - |
| Hot water output | - | 30 kW |
| Central heating output | - | 30 kW |
| ErP class | - | A |
| Seasonal efficiency | - | 94% |
| Weight | - | 32.3 kg |
| Hot water flow rate | - | 12.3 litres per minute |
Sources: Joule Cyclone Air 150L Direct, 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 Cyclone Air 150L Direct if...
A 150 litre direct unvented cylinder from Joule's Cyclone range, heated by twin immersion elements rather than a boiler or heat pump coil. It suits a property with electric-only heating or a holiday let, reheating a full tank in around 57 minutes.
Full Cyclone Air 150L Direct specifications →Buy or hire the Greenstar 4000 30kW combi if...
- you want one that comes with 9 years more warranty
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 Joule Cyclone Air 150L Direct and the Worcester Bosch Greenstar 4000 30kW combi?
The Worcester Bosch Greenstar 4000 30kW combi comes with 9 years more warranty. The Joule Cyclone Air 150L Direct is a direct unvented hot water cylinder, 150 litres; the Worcester Bosch Greenstar 4000 30kW combi is a gas combi boiler, 30 kW hot water output.
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