High
50-80 (ll-ll) on Ariston Clas HE 28

Your boiler is struggling to detect the temperature for your hot water supply, so it has stopped providing hot water to be safe.

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

D.H.W.thermistor faulty (open cicrcuit)

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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