Vaillant VR65 eBUS output drop to 1.9v

accom · 26 Sep 2023

Hello, I have a Vaillant EcoTEC plus624 boiler (2010 model), a Vaillant VRT392 thermostat, and a UniSTOR hot water storage cylinder connected to a Vaillant VR65 control center, now the problem is the VRT 392 suddenly stopped working which is completely dead, althrough I still have hot water but cannot control central heating without the thermostat.
I measured eBUS output from the boiler is 21.67V, but it comes out only 2V from VR65, which the VRT 392 requires a voltage between 9V-24V to operate, I need to ask if anyone knows whether the VR65 developed a fault.
thanks

Deleted member 267285 · 26 Sep 2023

It sounds like it. If you need heating, are you able to join the 2 wires together in a connector block and alter the temperature at the boiler temporarily?

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Vaillant VR65 eBUS output drop to 1.9v

accom

Deleted member 267285

DIYnot Local

Similar threads