BoilerFaultCodesWhat the manual says
Manufacturer manualInstaller Mode setting code
What causes this fault?
This occurs because the control knobs on the front of the boiler have been placed into a specific sequence used by engineers to test the system's performance. It is usually triggered accidentally during cleaning or when someone is trying to adjust the temperature settings manually. Because the boiler is waiting for programmed instructions from an installer, it pauses normal heating operation until the mode is deactivated.
DIY fix possible
Turn the DHW (Hot Water) thermostat knob fully clockwise then fully anticlockwise.Turn the CH (Heating) thermostat knob fully clockwise then fully anticlockwise.The display should return to the standard temperature reading.
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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