Low
A5 on Atag A200

Your boiler is struggling to detect the outdoor temperature, but it will continue to heat your home using its internal settings as a backup.

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.

What the manual says

Manufacturer manual

Outside temperature (only if an outside sensor is connected)

From this model's manual
Verified against the Atag A200 System installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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