BoilerFaultCodesTechnical description
Insufficient water pressure. Check pressure gauge reading, if low restore pressure (see 6.3.4) then re-set as described in code 01. Re-set as described for code 01.
What causes this fault?
This fault occurs when the internal water pressure drops below the minimum level required for the boiler to operate safely. The most common reason is a slow leak somewhere in your central heating system, though it can also happen if you have recently bled your radiators and haven't topped the pressure back up.
This fault is frequent in autumn when homeowners turn their heating back on for the first time after summer, often revealing pressure drops that occurred while the system was idle.
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.