BoilerFaultCodesTechnical description
Controlled characteristic pump has run dry
What causes this fault?
This fault occurs when the boiler detects that there is no water passing through the internal pump, causing it to spin without resistance. The most common reasons are a significant drop in system pressure or a large pocket of air becoming trapped inside the pump itself, which prevents it from being able to circulate heat. To protect the internal components from overheating or burning out, the boiler triggers a safety shutdown.
This issue is frequently seen in autumn when heating systems are turned back on after the summer, as air often settles in the pump or radiators during 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.