BoilerFaultCodesTechnical description
Operating modes of the two speed heating pump
What causes this fault?
This is not a mechanical failure, but rather a temporary status where the boiler is adjusting its pump to the most efficient speed for your heating requirements. It occurs when the control board is testing the circulation to ensure water is moving through the heat exchanger at the correct rate. Once the boiler confirms the flow is optimal, the code will disappear and normal operation will resume.
This is more common in autumn when the heating is first turned back on after summer and the system is recalibrating for regular use.
DIY fix possible
No action is required as this is a status message rather than a faultMonitor the display to ensure it progresses to a standard temperature readingIf the code persists for a long period, restart the boiler using the power button