Three zone setup wiring with ebus
My system is an a plan setup with an unvented hot water cylinder. I currently have nest controlling the heating, one for each floor with ground floor also controlling hot water, this is being totally replaced by tado and I have tado TRVs on each radiator
Does anyone know if the following is possible and if so would be able to advise on wiring?
Wireless extension controlling hot water and heating zone 1 (replaces one heatlink from nest).
Wired thermostat controlling heating zone 2 (replaces second heat link)
Wired thermostat controlling heating zone 3 (replaces third heat link)
All three thermostats would be set to take rooms as I never need them to directly call for heat (TRVs will control when boiler should fire) with a request to customer services linking each thermostat and the relevant TRVs into a zone (so one thermostat and all TRVs for the heating circuit in each zone)
The above should take the ebus capability if possible
Answers
-
It’s not possible to control 3 zones with ebus, even if you use Vaillant’s own thermostats. This is mainly due to Load Compensation not making sense when you have multiple zones with different heating loads.
Your Nests will be using relay control and you’ll need to do the same with Tado.
0 -
Thanks for the confirmation I really appreciate the response. Does the setup proposed seem fine if I use relay? If so do you know where I could find wiring diagrams?0
-
The proposed setup will work fine. If you are using the wireless receiver it is more or less a direct transfer of the wiring from the heat link to the receiver. However, if you are using an extension kit then you need to omit the bridging wires used for CH Com and HW Com. This is done internally with the extension kit.
To go from a heat link to a wired thermostat is a bit more convoluted. Tado thermostat is battery powered so there is no need for a Neutral. You just need to transfer the wires for CH Com & CH NO from the heat link to the thermostat.
Tado will provide diagrams for DIY installs, but not sure if they will in this scenario as it is a more advanced setup.
1 -
Thanks for your help I really appreciate it0
-
@GrilledCheese2 I’m hoping you can help me as you seem very knowledgeable on setup.
I am implementing what is mentioned in your previous message. I initially added the two thermostats to the zones without hot water control and they work perfectly with rooms being assigned to the individual stats as zone controllers. However when I added in the wireless kit to control the final zone with hot water it becomes the only zone controller available. I tried removing and re-adding the thermostats with no luck so I’m back with nest for that zone while I figure it out.
Do you know how to create the zones for the wireless receiver and two thermostats separately?0 -
You’ll have to get customer support to sort this out for you. Sometimes the installation process makes assumptions that aren’t correct.
Give them the IDs of the wired devices that you want to be zone controllers. While you’re at it give them the ID of the one thermostat you want to use to manually switch the hot water on/off.
1 -
Brilliant thanks again0
