BoilerFaultCodesWhat the manual says
Manufacturer manualWaiting period comfort safety mode
What causes this fault?
This status occurs when the boiler's internal sensors detect that the heat exchanger is getting too hot too quickly, prompting the system to pause to protect itself. It is usually caused by a temporary restriction in water flow or a minor mismatch between the heat being produced and how fast the pump can move it away. Once the temperature drops to a safe level, the boiler will automatically resume normal operation without needing a manual reset.
This code is more common during the first few cold spells of autumn when the heating is turned back on after a long summer break, often due to a slightly sluggish pump or air trapped in the radiators.
DIY fix possible
Check that all radiator valves are fully open to allow water to flow freelyEnsure there are no obstructions around the external flue pipeMonitor the boiler for several minutes to see if it clears the code and restarts on its own
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Related fault codes
All 101 fault codes on the ecoTEC Pro / ecoTEC Plus
Seeing a different code? Every code this model can display, in one place.