BoilerFaultCodesYour boiler is working exactly as it should and has simply paused because the water has reached the target temperature you set.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: The boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler
What causes this fault?
This code appears when the water inside the boiler has reached the specific temperature you selected on the control dial. The boiler temporarily shuts off the burner to prevent overheating while the pump continues to circulate that hot water around your radiators. Once the water temperature drops by a few degrees, the boiler will automatically fire back up to maintain the heat.
You may see this more frequently in the autumn or spring when your thermostat is active but your home is already relatively warm, causing the boiler to reach its target temperature quickly.
DIY fix possible
Check that your room thermostat is turned up high enough to demand heatWait for the boiler to cool down slightly, at which point the 'C' code will disappear and the boiler will fire up againEnsure your radiator valves are open to allow the heat to move away from the boiler
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A boiler cover plan would cover faults like C — no call-out fees, no surprises.
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