BoilerFaultCodesWorcester Bosch 204 Fault Code
The Worcester Bosch 204 fault code means: your boiler is currently taking a short break because it has reached its target temperature and is waiting for the water to cool down slightly before firing up again.. It appears on 23 Worcester Bosch models in our database.
Technical description: The boiler is waiting – the actual temperature is higher than the calculated or selected boiler temperature
What causes the Worcester Bosch 204 fault?
This occurs when the water inside the boiler has reached a temperature slightly higher than what the thermostat or control dial is asking for. To prevent overheating and save energy, the boiler temporarily stops the burner until the water temperature drops back down to a level where it can efficiently start heating again. It is a normal part of the boiler's operation, often seen when the building is nearly up to temperature or if the radiators cannot dissipate heat fast enough.
This code is more common during the autumn and spring, as the boiler frequently reaches its target temperature quickly when the weather is relatively mild.
DIY fix possible
Check that your room thermostat is set to the desired temperatureEnsure at least one or two radiators have their valves fully open to allow heat to dissipateWait 15-20 minutes to see if the code clears itself once the water temperature drops
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the 204 fault code
Click a model for the full fault code list and model-specific repair notes.
- 1000 Repair: £150-300
- 24 RSF
- 26 CDi Xtra
- 30i Junior Repair: £0-120
- 35 RSF Repair: £0-120
- Danesmoor Repair: £0-120
- GB162
- Greenstar 12i System
- Greenstar 2000 Repair: £120-250
- Greenstar 27CDi Repair: £120-250
- Greenstar 28CDi Repair: £120-250
- Greenstar 4000
- Greenstar 8000 Repair: £120-250
- Greenstar 8000 Life Repair: £150-300
- Greenstar 8000 Life System Repair: £120-250
- Greenstar 8000 Life/Style Repair: £120-£350
- Greenstar 8000 Style Repair: £150-300
- Greenstar CDi Compact
- Greenstar i Repair: £90-180
- Heatslave Repair: £0-80
- Hideaway
- Junior 24i
- Junior 28i Repair: £0-120
Source
Worcester Bosch 204 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026