High
7.iii on Chaffoteaux Celtic 2 24 Rsc

Your boiler has built up too much internal pressure, causing a safety valve to release water to prevent damage.

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

Safety valve discharges - Vessel lost air charge

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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