BoilerFaultCodesTechnical description
Burner in fault position. Flue gas temperature limiter has responded. Check the heating system water level and the pump. Vent the system.
What causes this fault?
This fault occurs when the boiler's internal components detect that the heat being produced isn't being carried away quickly enough, causing the system to overheat. The most common reasons are a failed internal pump that isn't moving the water, or a significant blockage within the heat exchanger that is restricting flow. It can also be triggered by a large pocket of trapped air or a dangerously low water level in the system.
This fault often appears during the first cold spell of autumn when a pump that has been idle all summer fails to restart or 'seizes' due to inactivity.
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.