C Low
Your boiler is working correctly and has simply reached the maximum temperature you set, so it is pausing temporarily until the water cools down enough to fire up again.
Technical description: The boiler has a call for central heating / hot water but the appliance has reached the desired temperature set on the boiler
Typical repair cost: £0 (including labour)
DIY fix possible
Check if your room thermostat or TRVs are set too lowEnsure at least one radiator is fully open to allow water to circulateWait for the boiler to naturally cool down and restart itself
Protect yourself from future repair bills
A boiler cover plan would cover faults like C — no call-out fees, no surprises.
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