BoilerFaultCodesTechnical description
Low Water Pressure
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 reasons are a slow leak somewhere in your central heating pipework or radiators, or a loss of air pressure within the expansion vessel which is meant to regulate the system. In some cases, it can also happen if you have recently bled your radiators without topping the water level back up using the filling loop.
This issue is frequently seen at the start of autumn when homeowners turn their heating back on for the first time after summer, as stagnant pipes can reveal slow-release leaks or pressure drops.
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.