F.03 - actoSTOR cylinder sensor interruption (with F.91)

What does F.03 mean?

There is an interruption in the circuit of the actoSTOR cylinder sensor (NTC). This fault occurs in combination with F.91, indicating a problem with the actoSTOR module.

• NTC sensor is defective or its cable is defective.
• Defective plug connection on the NTC sensor or on the actoSTOR electronics.

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 indicates an interruption in the cylinder sensor circuit of the actoSTOR module, requiring professional diagnosis.