BoilerFaultCodesTechnical description
System pressure low / No water in boiler
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe level, causing the boiler to shut down to prevent internal overheating. The most common reason is a slow leak somewhere in your radiators or pipework, or a failing component like the expansion vessel that can no longer manage pressure changes.
This issue often surfaces when you first turn the heating back on for autumn, as the sudden increase in heat and pressure can expose small leaks or weakened seals that occurred during summer.
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.
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