BoilerFaultCodesTechnical description
Dry fire protection (temperature gradient of flow NTC too steep) | .Air in boiler/system, pump blocked or defective, pump output too low
What causes this fault?
This fault occurs when the internal sensors detect that the water inside the boiler is getting hot far too quickly, which usually means the water isn't flowing away from the heat exchanger. The most common reason is a failing pump that can't push the water around, though it can also be caused by a large air bubble trapped in the pipework blocking the path.
This issue often appears at the start of autumn when the heating is turned on for the first time after summer, as pumps can seize up during long periods of 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.