BoilerFaultCodesTechnical description
Pump does not run. Possible causes: Operating switch (or programmer), hot water control thermostat, or control board fault.
What causes this fault?
This fault occurs when the boiler's internal pump fails to move water through the system, preventing heat from reaching your taps or radiators. The most common reason is a mechanical failure within the pump itself, but it can also be triggered if the electronic control board or the external programmer fails to send the necessary signal to start the pump.
This issue is frequently seen at the start of autumn when pumps that have sat idle all summer become seized or 'stuck' upon being restarted for the heating season.
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.