BoilerFaultCodesTechnical description
Dry fire protection (difference between flow and return NTC's too large) | No water in appliance, pump cable defective, pump blocked or defective, pump output too low
What causes this fault?
This fault occurs when the boiler detects a massive temperature gap between the pipes leaving the unit and those returning, suggesting that water has stopped circulating. The most common reason is a failed or jammed internal pump, but it can also be caused by a severe blockage in the system or air being trapped within the heat exchanger.
This issue frequently appears at the start of autumn when heating systems are switched back on after being idle all summer, which can cause the pump to seize.
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.