BoilerFaultCodesTechnical description
Service Function: Switching difference
What causes this fault?
This code appears when the boiler has been manually or accidentally switched into a specific service mode that adjustments the burner's firing behavior. It is usually triggered by someone interacting with the internal settings or the control dials in a specific sequence, rather than a mechanical component failing. While in this mode, the boiler pauses its normal operation to allow an engineer to test the temperature gaps between the flow and return pipes.
DIY fix possible
Turn the temperature control dials fully counter-clockwise and then back to your desired settingPress and hold the 'Reset' button for five secondsSwitch the main power supply to the boiler off and back on again after 30 seconds
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