BoilerFaultCodesTechnical description
Error in regulating combustion – possible error with the calibration values chimney gas valve and board.
What causes this fault?
This fault occurs when the boiler's internal computer loses the ability to correctly balance the ratio of gas and air needed for a clean flame. It is usually triggered by a communication failure between the main control board and the gas valve, or because the internal sensors have detected that the combustion quality has drifted outside of safe limits.
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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