Your boiler has temporarily paused operation because it is waiting for a clear reading from the internal water pressure sensor.

Waiting period – pressure sensor

What causes this fault?

This fault occurs when the boiler is unable to get a steady reading from the internal pressure sensor, often because the water pressure is fluctuating or at the very limit of its operating range. The most common reason is a slow leak in the system or air trapped near the sensor, which prevents the unit from confirming it is safe to fire up. In some cases, the sensor itself may be blocked with debris or failing, leading to inconsistent data being sent to the main control board.