BoilerFaultCodesTechnical description
To run the burner at minimum rate
What causes this fault?
This code appears because the boiler has been manually put into a specific testing mode by a person pressing buttons on the control panel. It is triggered when the service functions are activated to hold the burner at its lowest internal setting, typically so an engineer can take precise combustion readings. Because it is a manual setting rather than a mechanical failure, it simply means the boiler is following a specific command rather than encountering a problem.
DIY fix possible
Turn the mode selector knob away from the 'Service' or 'Test' positionSwitch the boiler off at the fused spur switch for 30 secondsSwitch the power back on to return the boiler to normal operation
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