Technical description
Water pressure too low
What causes this fault?
This fault occurs when the internal sensors detect that the water pressure has dropped below the minimum level required to circulate heat safely. The most common reason is a small leak somewhere in the central heating pipework or radiators, though it can also happen if you have recently bled your radiators without topping the system back up.
This fault is frequently seen in autumn when homeowners turn their heating back on for the first time, as the system struggles to reach pressure after a long period 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.