High
43 on Johnson Starley C16u

Your heater has stopped working because its internal temperature sensor has developed an electrical fault and can no longer read the air flowing back into the unit.

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

Return air temperature short circuit. Temperature sensor shorted to earth

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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