High
Error 04 on Atag Q 25S

Your boiler has detected an issue with its power supply or an internal electrical signal fluctuation, which has caused it to stop working for safety reasons.

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

adjustment or error for voltage interruption

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

Error 01View →Error 02View →

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