BoilerFaultCodesYour boiler is currently running a self-diagnostic test to check the water pressure and fill level as it prepares to start up.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Filling test program. The diverter valve moves to the centre position
What causes this fault?
This is a routine diagnostic phase where the boiler verifies there is enough water pressure to operate safely. It occurs when the appliance is first powered on or after a periods of inactivity, as the system checks that the internal valves are in the correct position. It is a sign the boiler is performing its internal safety checks rather than an indication that a part has failed.
DIY fix possible
Wait approximately 15 minutes for the program to finishEnsure your external or internal filling loop is closedCheck that the pressure gauge is between 1.0 and 1.5 bar
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