BoilerFaultCodesTechnical description
CH pressure loss/pressure sensor faulty. Check/replenish CH system pressure. Find leaks. Check/replace pressure transmitter and cable.
What causes this fault?
This fault occurs when the internal sensor detects that the water pressure has dropped below the minimum level required to operate safely. The most common reason is a slow leak somewhere in your radiators or pipework, but it can also happen if the expansion vessel has lost its air charge and can no longer stabilize the pressure.
This issue is more frequent in autumn when homeowners first turn their heating back on after summer, as the change in temperature can reveal small leaks or failed seals.
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.