Low
S.34 on Vaillant Combi Compact 242EB

Your boiler has entered a temporary frost protection mode to prevent internal pipes from freezing due to very low temperatures.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

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

Heating mode frost protection error

DIY fix possible

Check that your home heating is turned on at the thermostatEnsure any radiator valves in the room with the boiler are fully openWait for the boiler to warm up naturally as the code should vanish once the temperature rises

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Related fault codes

S.30View →F.28View →F.29View →

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