BoilerFaultCodesTechnical description
Pump-related faults – the pump could have failed, it may have over run or there could be an issue with the airlock
What causes this fault?
This fault occurs when the boiler detects that water is not moving through the system quickly enough to safely carry heat away from the burner. The most common reasons are a circulation pump that has seized or lost power, or a large pocket of air trapped within the unit that is blocking the flow of water. In some cases, it can also be triggered by a build-up of debris or sludge that has restricted the internal pipework.
This issue often appears in autumn when the heating is turned on for the first time after summer, as pumps can seize if they have been sitting idle for several months.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.