vSMART app shows 'Boiler communication error' and boiler may revert to basic operation or stop responding to vSMART commands.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety warning: Isolate mains power to the boiler before accessing any internal wiring. Only qualified personnel should remove boiler covers.
Steps to check:
- Power cycle both units: Turn off the boiler and vSMART interface/gateway for 30 seconds, then power them back on.
- Check compatibility: Confirm that your Vaillant boiler model and firmware are listed as compatible with vSMART in Vaillant documentation.
- Inspect eBUS wiring: With power off, check that the eBUS cable is correctly connected, not reversed (if polarity matters), and not damaged.
- Check boiler for own errors: Look at the boiler display for any error codes that may indicate an internal control board issue.
If communication cannot be restored and the boiler shows persistent bus errors, a Vaillant engineer should test the boiler control board and vSMART interface and replace faulty components.
Repair Difficulty
Required Part
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