High
t6 on Worcester Bosch Greenstar CDi Compact

Your boiler is performing a routine internal safety check on the component that detects the flame, but it has identified a fault in its ability to monitor this safely.

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

Ionisation oscillator test. Tests the flame detection circuit. Ionisation circuit is switched on. An A.C. voltage of approximately 150 Volts can be measured between the ionisation probe and earth.

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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