BoilerFaultCodesTechnical description
Control stop from 3 till 10 minutes: set flow temperature (t1) has already been reached and the heating demand still exists.
What causes this fault?
This happens when the water inside the boiler gets hot much faster than the rest of your radiators, often because the heat cannot escape the boiler quickly enough. It is usually caused by restricted water flow, which can happen if your pump is slowing down, your heating filter is blocked with debris, or too many radiator valves are turned off at once.
This code is more common in autumn and spring when your heating is only needed in short bursts or when individual radiator thermostats are mostly closed.
DIY fix possible
Check that all radiator valves are fully open to allow heat to escapeEnsure the central heating bypass valve is not closedWait up to 10 minutes for the boiler to automatically restart