New installation with Vaillant - questions and doubts

mlc

Hi!

I've decided it's time to upgrade my old heating installation with some smart devices. Tado seems the obvious choice, but I would like to make mysefl sure about a few things, before I spend a lot of money on it.

 

Current situation:

I have a Vaillant ecotec plus VC PL 246/3-5 with calormatic VRC 430 installed right into it. Additionally there's a weather sensor outside, but no other thermostats in the room. Vaillant is heating the water tank, radiators and underfloor heating in the kitchen and bathrooms. All the heating is set into one circuit (HK1), including underfloor heating. I have no wiring for underfloor, no actuators. The only way to control it is a single global three-way thermostatic mixing valve that controls the temperature of the whole underfloor installation.

 

Goals:

Savings of course :) Mostly due to better scheduling of heating + ability to individually steer/reduce temperature in unused rooms.

 

Questions/doubts:

1. Will the extension kit work in modulation mode when simply connected to pins in Vaillant , marked as BUS (next to 7-8-9)?
2. Will I be able to control the heating in the water tank as well?
3. I want to install about 6-8 smart valves for the radiators in individual rooms. Due to costs and lack of wiring I really would like to avoid buying more thermostats. Is it possible that valves will also “call for heat” on their own? I’ve read some discussions about this possibility after contacting Tado support and changing configuration (?!). Can you please confirm that?
4. As far as I understand, there’s no way to use external thermometers with Tado valves in the rooms? I’m using HomeKit and Home Assistant and already have a few devices measuring temperature in the room, that could be used – Netatmo Weather Station with additional modules, AC sensors etc.)
5. Underfloor heating – as I said – no wiring, no actuators and it’s pretty impossible now to lay wires to the rooms with underfloor heating and using both wired thermostats by the manifold and additional wireless in the rooms sounds extremely expensive. But since they are in bathrooms and kitchen only, I can accept global steering of that. So if I won’t do any wiring in the manifold and simply put wireless thermostat in on of those rooms to call for heat if it gets too cold, and limit maximum temperature with the current three-way valve, is it going to work fine?

Alternatively, I have to change this three-way valve anyway (it’s broken). But since it's not just a thermostatic head, but a mixing valve, I believe there's no way to control it with tado valve? 

Thanks for all your help, hopefully with your hints I’ll join the community of Tado users soon.

 

mlc

For some reasons I couldn't add photos to the first post, so here they are - connection in Vaillant and mixing valve for my underfloor heating.

johnnyp78

You won’t be able to do a lot of what you want. Tado has limited support for vaillant ebus so you’d need to check the model’s compatibility first. Usually you can’t use digital connections with system boilers anyway though I think with vaillant if you source some discontinued equipment you can (assuming Tado supports that boiler). I doubt you’d be able to continue to use weather compensation if you got it all working.

Tado trvs can call for heat. You can’t use third party thermostats with it. As far as I’m aware there’s no official support for mixing valves, unless you mean y-plan style three way valves, which Tado can support with the wireless receiver. I don’t know much about UFH though.

mlc

Thank you. Do you know where can I find info on compatibility with my boiler? Is there any list somewhere or should I rather contact Tado support?

johnnyp78

Contact Tado support. I think with a complicated set up like that you’ll be entering a world of pain with Tado but maybe you’re up for the challenge.