High
10.ii on Chaffoteaux Celtic 24 HE

Your boiler is rapidly turning itself on and off because a safety sensor thinks it is overheating, preventing it from heating your home properly.

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

Rapid cycling high/low or high/low/off - Limit stat out of calibration

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

10.iView →

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