F49 Fault — eBUS short circuit or overload

What does F49 mean?

A short circuit or overload has been detected on the eBUS communication system, or two power supplies with different polarities are connected to the eBUS.

• Short circuit on eBUS
• eBUS overload
• Two power supplies with different polarities on the eBUS

Click steps to track your progress.

1. 1

   Check the wiring into the eBUS for any damage or short circuits.

2. 2

   Ensure that only Vaillant controls are connected to the eBUS.

3. 3

   Verify the polarity of any connected power supplies to the eBUS (requires specialist tools).

4. 4

   If issues persist, the PCB may be faulty (contact a technician).