Worcester Bosch Greenstar 4000
The Worcester Bosch Greenstar 4000 is a mid-range boiler with a full-colour display, aimed at small to medium homes.
At a glance
- Configurations: Combi, System
- Best suited to: Small to medium homes with one bathroom
- Fuel: Mains natural gas (some variants are LPG-convertible, check the manufacturer’s data).
Specifications
Match the badge in front of you to a row before you use any of this. Every figure below was read from the Worcester Bosch literature listed under Sources at the foot of this page, checked 6 September 2026. Outputs, variants and part numbers change by year, so the appliance data plate is still the last word.
| Variant | Output | GC number |
|---|---|---|
| Greenstar 4000 25kW combi (GR4700iW 25 C) | 25kW | 47-800-30 |
| Greenstar 4000 30kW combi (GR4700iW 30 C) | 30kW | 47-800-32 |
| Greenstar 4000 12kW system (GR4700iW 12 S) | 12kW | 41-800-07 |
| Greenstar 4000 15kW system (GR4700iW 15 S) | 15kW | 41-800-09 |
| Greenstar 4000 18kW system (GR4700iW 18 S) | 18kW | 41-800-11 |
| Greenstar 4000 21kW system (GR4700iW 21 S) | 21kW | 41-800-13 |
| Greenstar 4000 24kW system (GR4700iW 24 S) | 24kW | 41-800-15 |
- These are the natural gas GC numbers printed in Worcester's own installation manuals. The 30kW combi on LPG is 47-800-33, not 47-800-32, so check the appliance type code on the badge first.
Where the data plate is
Centrally on the bottom of the appliance, in line with the control panel, with the additional type plate on the underside. One badge carries the model, the serial number and the GC number.
Reading the plate
Worth knowing on site
- Full-colour text display and a quiet-mark design.
- Combi and system options; check the specific output on the data plate.
On the tools
Sitting between the entry 2000 and the flagship 8000, the 4000 is a common choice where a customer wants a step up in display and finish without paying for the largest outputs. Its quiet-mark design is often mentioned by engineers fitting it in open-plan kitchens.
Variants and configuration
Available as combi or system, the 4000 spans a wider output band than the 2000, so two 4000 installs can look quite different in practice. The full-colour display is a useful cue on site for telling a 4000 apart from its plainer sibling.
Where it sits in the range
The 4000 occupies the middle tier of Worcester Bosch's current Greenstar range, positioned as the everyday mid-market option. It commonly replaces an ageing combi in a three-bedroom home where the original appliance no longer keeps up with hot-water demand.
Finding the manual and the data plate
For the exact outputs, gas rate, dimensions and commissioning figures, work from the appliance’s data plate and the manufacturer’s installation and servicing instructions. The GC (Gas Council) number and serial are on the data plate, usually behind the front panel or on the underside. Worcester Boschpublishes its manuals and support at Worcester Bosch support.
Frequently asked
Useful while you’re on the tools
More from Worcester Bosch
Manifold is not affiliated with or endorsed by Worcester Bosch. Brand and model names are used only to help engineers find the right resources. Specifications and available variants change by year and model, so always work from the appliance’s data plate and the manufacturer’s own installation and servicing manual. Gas work must be carried out by an appropriately Gas Safe registered engineer.