F.81 - actoSTOR charging pump defective (with F.91)

What does F.81 mean?

The actoSTOR charging pump is defective, resulting in the cylinder not being fully charged within the specified time. This fault occurs in conjunction with F.91, relating to the actoSTOR module.

• Cylinder is not fully charged after the specified time.
• Cylinder charging sensor and/or cylinder sensor are defective.
• Air present in the actoSTOR pump.
• Defective cable harness for the pump, impeller sensor, limiter, diverter valve, secondary heat exchanger, or the pump itself.

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 a problem with the actoSTOR charging pump, potentially due to air, a blocked heat exchanger, or a defective pump, requiring professional diagnosis.