Tuya valves (TRV's) with OpenTherm connection to Vaillant boiler

Hi, i’m investigating how i can setup Tuya TRV’s with a Vaillant boiler. I want the system to be modular setup to be efficient. I understood that either your vaillant boiler should already have a OpenTherm connection or you should ad a VR33 OpenTherm interface. I don’t need a central thermostat but wouldn’t mind using one. I want to be able to heat every room separately. I would like to use these TRV’s (link). What do i need else to be able to controle my Vaillant boiler? Does anyone have experience with such a setup?

I’m replying to my own message because i can’t understand that no one has a similar setup. If you have a setup like this please let me know. i could use some help!

Hi, maybe I am searching for the same answer.

I have opentherm viesmann boiler, few smart radiator valves and non-smart opentherm thermostat from playbock.

Currently, I have esp8266 with opentherm gateway shield by mr. Praus between the playbock thermostat and the boiler and experimenting with overriding the OT commands.

@halecivo , so nice that you send a message. How far are you with your setup?

Hello @fschade , sorry for late reply. I was basically in the point where I calculated target temperature from an equitherm curve and compared it to temperature sniffed from my room thermostat Electrobok BT52. Time to time I tried to update curve parameters to better fit my needs.

I uploaded new firmware over the air.

However from time to time I uploaded wrong firmware making it impossible to upload it via wifi, so I had to rewire the thermostat and disconnect my gateway to upload corrected firmware by pc, which end up one day by being to lazy to connect it back, so now it waits for another shot.

Code is private on github, but I could give you access if you would be interested - but as I said - it’s more a playground experiment than something to use.

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Have either of you made any progress? I’ve got a Vaillant heater that I could equip with an OpenTherm module, and I’ve just installed Nedis valves in every room (rebranded Tuya, most likely). Would be nice to turn off the heater if none of the rooms needs heating.


Can you give me access to that repo?

Thanks in advance.

I did not do anything yet. I first need to replace the valves on all the radiators. But still interested in any progress you guys make.