BoilerFaultCodesWorcester Bosch 265 Fault Code
The Worcester Bosch 265 fault code means: your boiler is temporarily pausing because it is producing more heat than your radiators or hot water system can currently use or circulate.. It appears on 14 Worcester Bosch models in our database.
Technical description: Heat demand lower than energy supplied
What causes the Worcester Bosch 265 fault?
This occurs when the boiler generates heat faster than your central heating system can carry it away, often because too many radiator valves are turned off or the internal pump is struggling to move the water. As a safety measure, the boiler briefly pauses to allow the internal temperature to drop before attempting to fire up again. This is frequently caused by a lack of 'bypass' flow or all your thermostatic radiator valves (TRVs) closing at the same time.
This code is more common in spring and autumn when only one or two radiators are turned on, making it difficult for the boiler to shed its minimum heat output.
DIY fix possible
Ensure at least two or three radiators have their thermostatic valves (TRVs) turned up to maximum.Check that all radiator valves are open and not stuck closed.Verify that your room thermostat is set to a temperature higher than the current room temperature.
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Worcester Bosch models that show the 265 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24/28/35 CDi MkII Repair: £150-300
- Greenstar 1000 Repair: £120-250
- Greenstar 12i System
- Greenstar 2000 Repair: £120-250
- Greenstar 27CDi Repair: £120-250
- Greenstar 28CDi Repair: £120-250
- Greenstar 30i Repair: £80-250
- Greenstar 4000 Repair: £120-250
- Greenstar 8000 Life & Style Repair: £0-120
- Greenstar CDi Compact Repair: £120-250
- Greenstar i
- Greenstar Ri
- Hideaway 90 Repair: £0-120
- Junior 28i Repair: £0-120
Source
Worcester Bosch 265 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
- Worcester Bosch 24/28/35 CDi MkII manual (PDF)
- Worcester Bosch Greenstar 1000 manual (PDF)
- Worcester Bosch Greenstar 12i System manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026