When a trv requests heat: how to trigger actual warm water being provided.

[tim-vk]

So I'm checking if this will solve my problems i'm having:

Currently I have a 100% tado system (running without home assistant). But due to range issues I want to add some other zigbee trv's.
The issue is: How do i set this up in such a way that: if a zigbee trv is set to a high temperature the central heating will actually start?

It will all work fine if one of the tado thermostats also has to provide heat. But if they are set to off (as often happens in my home) it won't work.

[MadCyborg315]

I think what you need is to make an automation that requests heat from your boiler (or whater ever is providing the heat) when a BT is in hvac mode "heating".

[tim-vk]

The annoying thing is: As far as i'm aware Tado does not have a simple "Please heat now" setting somewhere. The only way I could imagine was by setting the requested heat high for a room with a tado thermostat (which i can do with automations).

But that will also result in heating that specific room. Which i rather not do.

I would expect this pluging to have a "boiler thermostat" or something where you would set the thermostat that's connected to the boiler.
Or I'm completely misunderstanding how thermostats work. might also be the case.

[MadCyborg315]

What's your heat source? E.g. in my case, it's a gas boiler. I have a wall thermostat (simple clock with a relay). The wall thermostat triggers the boiler via closing a dry contact. I wired a shelly dry contact in parallel so I can switch on the boiler indepently from the wall thermostat. And my automation does exactly that: When a BT switches to heating, the shelly closes the contact and the boiler starts to supply heat.
Maybe this is any helpful for you.

(I'm not aware what Tado can and can't do.)

[tim-vk]

Tado is currently connected with opentherm (so are many other thermostats).

Didn't evenconsider just using a relay in parallel but that should work nicely! I did find a opentherm gateway. But my hope would be to use a smart thermostat without additional hardware added to it (and i'm not really sure if you can add a heat request with an opentherm gateway, anyone has experience with that?).

[ronaldt80]

Yes, try SAT, this will transform your open therm gateway into a fully functional thermostat.

https://github.com/Alexwijn/SAT