BoilerFaultCodes.com
Indicator light flashes slow (constant interval) High Lockout

Your boiler has detected a general internal fault and has stopped working to prevent damage or safety issues.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Fault condition

What causes this fault?

This fault occurs when the boiler's internal computer detects an interruption in the sequence required to maintain a safe flame. The most common reasons are a failure to produce a spark at the burner or the control board losing communication with essential mechanical parts like the fan. Essentially, the system has detected that it can no longer guarantee safe operation and has shut down as a protective measure.

Typical repair cost £100-350 (including labour)

DIY fix possible

Locate the reset button on the front control panel.Press and hold the reset button for approximately five seconds.Wait to see if the blue light stays solid and the boiler restarts.

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