BoilerFaultCodesTechnical description
Max. heating output
What causes this fault?
This code appears when the boiler has reached its highest possible heat production and is working at full power to meet the demand you have set. It is often triggered if the thermostat is set very high or if the heating system is trying to warm up a very cold house quickly. It is considered a status message rather than a mechanical failure, indicating that the system is simply running at its limit.
This display code is most common during the first cold snap of winter when the heating is turned on after a long break and the boiler has to work harder to reach the target temperature.
DIY fix possible
Check that your radiator valves are fully openEnsure the system pressure is between 1 and 1.5 bar on the front gaugeTurn the heating control knob down slightly and restart the boiler