F.80 - Secondary heat exchanger inlet sensor interruption/short circuit (with F.91)

What does F.80 mean?

This fault indicates an interruption or short circuit in the secondary heat exchanger inlet sensor. It occurs in conjunction with F.91, relating to the actoSTOR module.

• NTC sensor is defective or its cable is defective.
• Defective plug connection on the NTC sensor or on the actoSTOR electronics.
• sensor plug has a short to earth to the casing, or a short circuit in the cable harness.

Click steps to track your progress.

1. 1

   Press the reset button on the boiler display up to three times to try and clear the fault.

2. 2

   This fault is related to the actoSTOR module (F.91). Ensure the actoSTOR communication is working correctly by checking for other related faults.

3. 3

   Contact customer service. This fault points to issues with the secondary heat exchanger inlet sensor, its cable, or plug connections, requiring professional diagnosis.