Medium Lockout
Burner indicator Flashing on Glow-worm Betacom

Your boiler has detected a simple operating error that usually means a control knob is in the wrong position or the system needs a basic restart.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Error. Check the Hot Water knob for correct position and reset the boiler by turning the left knob on (reset) position for a few seconds.

What causes this fault?

This fault usually occurs because one of the control knobs has been left in a 'transition' or 'off' position, preventing the software from starting the ignition sequence. It can also be triggered by a minor communication glitch between the user interface and the main circuit board. In most cases, the boiler is simply waiting for a clear signal from the dials to confirm which mode it should be operating in.

DIY fix possible

Check that the Hot Water control knob is set to a normal temperature positionTurn the left-hand control knob to the 'Reset' positionHold it for a few seconds, then turn it back to your desired setting

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