Technical description
Temporary error – no input of parameters C1/C2. Printed circuit board (PCB) not configured.
What causes this fault?
This fault occurs when the boiler's main control board has lost its specific identity settings or has recently been replaced without being programmed. It physically prevents the boiler from firing because the system doesn't know which model size or fan speed settings to apply, essentially leaving the appliance in a 'blank' factory state. This is usually caused by a memory failure on the circuit board or a missing configuration plug.
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.