Opentherm

Java_Ju

Hi all, long time tado user with a new setup question?

I've recently had a new boiler fitted (ideal logic max C35) and I'm struggling to get the system working on opentherm with my setup.

I have:-

Internet bridge V2
Smart thermostat
Extension kit
7 x TRV's

With the extension wired to the boilers opentherm connections and set up through the smart thermostat using the professional installer low voltage settings, the boiler is on constantly. This is more pump circulating/fan on anything else but interestingly the boiler isn't recognising the opentherm connection.

If I take out the extension and wire in the smart thermostat direct, then the system works fine and shows on the boiler as an opentherm connection.

This does show that tado and the boiler can work together but I obviously need the extension to work the 7 xTRV's.

The system works fine connected to the boiler stat connection but that's not the most efficient way to use it.

Anyone able to help?

Regards

Julian

Java_Ju

For anyone that is interested i changed the extension for a new one and everything is fine and dandy!
They must have updated the extensions since I originally installed mine a few years ago.

Markjm

Hi Julian, was it easy to wire in to your new ideal boiler? Mine is about to be changed from an old Worcester to ideal.

johnnyp78

Which model is it? Ideal vogue boilers are very easy to wire Opentherm, I think logic are similar.

johnnyp78

Though as Julian has found, Tado have removed Opentherm support from their uk extension kits, so if you want to use it you’ll need either an EU version, to wire the smart thermostat to the boiler or to buy an old extension kit second hand.

Java_Ju

Hi mark, in answer to your question, yes it was very easy from memory but I couldn't understand why it didn't work.
The problem I had and which tado support couldn't answer was that my extension was a very early model and didn't have support for opentherm built in. I took it upon myself to replace it with an identical looking newer one and it worked straight away.
Everything was setup through the wall thermostat.

Hope that answers your question

Regards

Julian

Markjm

Thanks Julian & Johnny.

Boiler will be changed on thursday for an ideal logic.

I have what is probably a v2 extension kit, but also have an unused v3+ starter kit hanging about the house so hopefully one way or another i'll get it working!

johnnyp78

Check the extension kit has plus and minus symbols on the far right rather than saying ‘parking’. If it does you’re good to with Opentherm.

sygey

Hello! Can you please tell me how to connect this thermostat in OpenTherm mode? I saw that in the instructions it shows that digital + - 2 wires, what I am not clear about is that it somehow needs a 24v transformer? or do you just connect to the digital + - those 2 wires and directly to the gaz boiler open therm terminal? I mention that for power supply I have a separate cable with a plug for the outlet.

johnnyp78

I think grilled cheese already answered this. You connect the two wires from + and - to the Opentherm terminal on your boiler. If it’s a wired thermostat it’s battery powered, if it’s a wireless receiver it will need a power supply, which you have.

Salim

Hi Gents
Need your guidance.
We have Ideal Logic C35 which is opentherm. Also bought Tado wireless EU version 3+.
I am very confused. How can I ensure that opentherm is working. Do we need to buy anything else or it maybe simple now as using EU version

johnnyp78

You wire it in as per the long discussion above. Tado should give you instructions.