Your boiler is experiencing a temporary communication error or a sensor timing issue that is causing it to pause current operations.

Temporary fault code (Refer to section 7.10)

What causes this fault?

This fault typically occurs when the main control board loses communication with the internal temperature sensors or when those sensors report conflicting data. It acts as a temporary pause while the boiler tries to verify that the readings are accurate and safe for operation. The most common reason is a degrading sensor (NTC thermistor) that is beginning to send inconsistent electrical signals to the brain of the boiler.