Technical description
Low water pressure or No water in boiler
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below the minimum level required for the boiler to heat up safely. The most common reason is a slow leak from a radiator valve or pipework, though it can also happen if you have recently bled your radiators and didn't top the pressure back up.
This fault often appears when you turn your heating back on for the first time in autumn, as small leaks or air pockets may have developed during the months 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.