BoilerFaultCodesWorcester Bosch 1013 Fault Code
The Worcester Bosch 1013 fault code means: your boiler has reached its maximum power limit while trying to heat your water, and it has stopped for a short time to prevent overheating.. It appears on 8 Worcester Bosch models in our database.
Technical description: Max. combustion point reached
What causes the Worcester Bosch 1013 fault?
This fault occurs when the boiler generates more heat than the system can successfully carry away, leading to a sudden temperature spike. The most common cause is a restriction in water flow, often due to a failing internal pump or a buildup of sludge and debris blocking the main heat exchanger. It essentially means the boiler is working too hard to push heat into a system that isn't circulating properly.
This issue often becomes more apparent during winter when the boiler is required to run at higher power levels for longer periods to meet central heating demands.
DIY fix possible
Check that all your radiator valves are fully openEnsure your system pressure is topped up to between 1.0 and 1.5 barPress the 'Reset' button on the front of the screen to clear the temporary lockout
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Gas Safe Register →Worcester Bosch models that show the 1013 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 1013 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