Moving to Opentherm Control

toekneeheart

Hi All,

I've got myself a bit confused and hoping the wise heads in the forum can assist.

We've had a Tado V3+ system with multiple TRVs for a few years now. It has worked well. I installed it myself and it was the zenith of my DIY career 🤣. This was in combination with a Worcester Bosch Greenstar 18i System Boiler that was in place when we moved into the house.

Sadly this recently died and needed replacement. After much reading, we plumped for a Viessmann Vitodens 100-W (B1KF) Combi Boiler. This was based on the understanding that it was a solid Opentherm compatible boiler whereas the new Worcester Bosch models do EMS2 which Tado doesn't speak.

We also moved to a combi system because we wanted the extra space freed up by losing the hot water cylinder and to be rid of the very loud shower pump we had. Install went well but the engineers were somewhat mystified by the Tado. Eventually they managed to wire it so it works.

My understanding however is that our existing setup won't do Opentherm and it simply will do relay on-off at this point. So I've bought the Tado Add-On Wireless Receiver (EU) to replace the existing UK Wireless Receiver. But at this point I am a bit bamboozled about what to plug into what.

This is what my current Wireless Receiver looks like:

And this is what the new one looks like:

I originally thought that this would be fairly simple!

Any advice would be MUCH appreciated! Cheers!

CiupaSs

for opentherm, it is digital 36v but if you put there these 2 cables from 230v you will destroy it

take a picture of your boiler cables, and how they are connected inside

cover your serial number and auth code

you need to connect 2 cables from the opentherm boiler to 36v on your receiver and configure it in the Tado Pro app for opentherm