BoilerFaultCodesTechnical description
Check room thermostat batteries
What causes this fault?
This fault occurs when the wireless connection between your wall thermostat and the boiler is broken because the transmitter has lost power. Without charged batteries, the thermostat cannot tell the boiler to turn on, leading the system to assume there is a communication error. The most common reason is simply that the batteries have reached the end of their life and need replacing to restore the signal.
This issue is frequently seen at the start of autumn when homeowners turn their heating back on for the first time and discover the batteries have drained over the summer months.
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.