High
S.39 on Vaillant Atmomax

Your boiler has paused its operation because a safety sensor has detected that an external component, such as an overflow pump or a temperature limit switch, has been triggered.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Burner off contact has been triggered this could be because of contact thermostat or condensate pump

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.20View →S.36View →

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