Medium
04 on Atag Q 25S

Your boiler has experienced a power interruption or an electrical stability issue, causing it to temporarily lose its settings or shutdown.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

adjustment or error for voltage interruption

From this model's manual
Verified against the Atag Q 25s installation & service manual, page 39.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Locate the boiler's fused spur switch or the dedicated circuit breaker in your fuse box.Switch the power off for 30 seconds to allow the internal electronics to reset.Switch the power back on and check if the boiler restarts and the error clears.

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