BoilerFaultCodesTechnical description
Check the system’s pressure and refill if necessary. Reset the boiler, if the fault reoccurs then you need to contact a heating engineer.
What causes this fault?
This fault occurs when the water levels inside your heating system drop below a safe operating limit, preventing the boiler from firing up to avoid damage. The most common reasons are a small leak somewhere in your radiator circuit or the need to bleed air from your radiators, which reduces the overall pressure. In some cases, a component inside the boiler like the expansion vessel may have failed, losing its ability to maintain steady pressure.
This fault is frequently seen in autumn when homeowners turn their heating back on for the first time after summer, 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.