Will any of the thermostats work with an Atag iC Economiser 27?

brewmook

Hi,

I have an Atag iC Economiser 27 boiler from 2017, not the more recent "plus" model. It came with an Atag One controller which is hooked in with a 2 write OpenTherm bus connection.

That controller is about to pack in and I'm looking at Tado instead.

I've read that the only UK model that does OpenTherm is the wired thermostat. Is that still the case?

Tado support said I'd need the "One BCU" module for this to work. I'm interested in the details of what that is and why it's needed, but didn't want to bug a clearly busy Tado support person. Can anyone elaborate?

Atag themselves are touting Tado on their website, so clearly something works, maybe just not this model. Their support folk aren't too willing to discuss these kind of details with non-accredited installers.

Why won't the OpenTherm bus connection "just work"?

Why can't I just use the basic on/off connector (aside from the lack of boiler modulation)?

I really don't care if the solution is wired or wireless, is there any feasible option for me?

Thanks,
Dave.

johnnyp78

I can’t help much, but Tado will definitely work on a relay connection. If you’re already using an Opentherm connection, I can’t think of any reason why Tado also wouldn’t work, unless your current controller is actually using a different protocol such as ebus.

frankfromfolkestone

Yes. I have a pre 2018 Atag iC Economiser 27 and I have setup Tado X Wireless receiver X using the Open therm connection and everything is working correctly.

I'm only writing this so others can see that it does work fine with Atag as I couldn't find any info and adding my boiler to the Tado app for initial setup wouldn't work as it doesn't have all the Atag models.

I just used Atag and said the controller was a Nest E and followed the instructions from there.

Very simple but I don't understand why the Tado app doesn't have the Atag One Controller in it as an option