BoilerFaultCodesTechnical description
Burner modulation limitation. The burner modulation limitation is activated.
What causes this fault?
This status occurs when the boiler detects that heat is building up too quickly or cannot be circulated away from the unit effectively. It physically limits its own power to prevent overheating, which is often caused by valves being closed on radiators or a pump that is struggling to push water through the system. Essentially, the boiler is waiting for the water temperature to stabilize before it resumes full operation.
This is more common during shoulder seasons like spring or autumn, when radiators are frequently turned off in individual rooms, reducing the overall flow of water the boiler can use.
DIY fix possible
Check that all radiator valves are fully open to allow heat to move away from the boilerEnsure the system pressure is between 1.0 and 1.5 bar on the digital displayWait up to 15 minutes for the status code to clear automatically as it is often part of normal operation