High Lockout
19 on Glow-worm Ci Range

Your boiler has stopped working because its internal temperature sensor has lost contact with the pipework or is failing to send a signal.

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

Central heating NTC not connected to pipe

What causes this fault?

This fault occurs when the boiler's main control board can no longer detect an accurate temperature reading from the flow pipe. The most common reason is that the clip-on sensor has physically vibrated loose or a internal wire has become disconnected, preventing the boiler from safely monitoring heat levels.

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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