Vaillant Boilers, Nest and Opentherm

[ShaunCorbs]

Won’t work as you can’t use ebus and on off at the same time

 

[tonyramponi]

Thanks, so in other words the ebus has priority over both the 24v and 230v thermostat switches?

The only reason I was thinking it might be the other way round was the need to install the jumper wires on the other terminals when using the ebus. I.e Why do you need the jumper wires?

I was thinking that using the nest to replace a jumper wire would allow it to override the ebus until the nest demanded heat. When the nest is demanding the jumper wire would be back in place and the ebus would back in control.

I could quite easily make something to disconnect the ebus when the nest is in set-back mode and switch it back in when the opposite is true but this probably too much of a dirty hack with unknown consequences. My original idea doesn't feel quite so dirty if the ebus is just ignored when a jumper is effectively removed.

 

[Jerry]

Put an hourly rate (£/hr) on your time. Then estimate the amount of time you guess you would spend trying this, before giving up and/or breaking something. Then add on the additional time you would spend being annoyed if you had managed to get the system partially working but not exactly how you would want it.

When you have this total, compare it to how much a plug-and-play unit would cost. Then go from there.

Don't forget to add the time you have spent on the forums.

And not a single mention of warranties etc

😆