BoilerFaultCodesTechnical description
Boiler is in waiting period of operation, blocking function as a result
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature is rising too quickly, suggesting that heat isn't being moved away from the boiler fast enough. The most common reasons are a lack of water flow through the pipes, a building up of sludge blocking the heat exchanger, or a pump that is beginning to fail. Essentially, the boiler pauses to prevent itself from overheating while it waits for the water temperature to stabilise.
This code often appears when the heating is first turned on after summer, as pump components can seize or become stuck during long periods of inactivity.
DIY fix possible
Ensure all radiator valves (TRVs) are fully open to allow water to flow.Check that the boiler pressure is between 1.0 and 1.5 bar on the digital display.Check for any trapped air by bleeding your radiators.