F90 - Communication fault with actoSTOR module

What does F90 mean?

The Vaillant Ecotec Plus Boilers are reporting a communication error, specifically with the actoSTOR module. This means the boiler cannot properly exchange information with the module, potentially affecting hot water storage functions.

• Faulty cable harness between the boiler and the actoSTOR module (EBus connection).

Click steps to track your progress.

1. 1

   Check the cable harness connecting the boiler to the actoSTOR module for secure connections.

2. 2

   Inspect the cable harness for any visible signs of damage, cuts, or loose wiring.

3. 3

   If the actoSTOR module is not meant to be used with your setup, ensure setting D.092 is correctly set to 0.

4. 4

   If the cable appears fine and the setting is correct, contact a qualified technician for further diagnosis.