Separate Zone for UFH on Vaillant system

Hi capri,

The VR 65 control centre was replaced with a VR 61 control centre as this allows 2 central heating zones, plus hot water.

A VR 81 remote thermostat was installed in the new kitchen/dining/sitting area, which is the new area being heated by the underfloor heating. This thermostat has to be wired upto the VR 61 and it allows a temperature to be set separately to the existing VRC 430 weather compensator thermostat, although all settings can be changed through the VRC 430. So the VR 81 controls the temperature of the new UFH area and the existing VRC 430 controls the setting of the existing CH.

Unlike on newer systems, the VR 61 doesn't offer an additional heating curve, so there is only one and this controls the existing central heating and the new underfloor heating, although, as I mentioned there are two zones, so different temperature settings (and setback temperatures) can be set for the UHF and CH.

The manifold has a thermostatic blender and pump built in, but a new zone valve was required to control the flow of water to the manifold. I used a Guardian Smartzone Pro 22mm 2 Way Zone Valve, which I was advised was better for UFH circuits. It's a nice valve!

I haven't needed to install a Low Loss Header or a bypass valve and everything is working well (touch wood). In fact you could argue it is working too well as the floor tile nearest the point at which the three UHF circuits attach to the manifold in the garage has cracked, and I suspect this is due to the change in temperatures (this is the warmest area of the kitchen), although it may have been cut and fitted badly as it is an L shaped tile so does have a week point!
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Many thanks for the reply. Another quick one related to the controls. Is it possible to reverse the order? ie the 430 (or 470F) to control the UFH and VR81 to control the rads (CH)?
I just came off the call with Vaillant tech support and their response was:

"If using one heating zone (for rads) and one UFH and a cylinder with a System Boiler (newer ecotec 600+ series) then you can use:

- VRC 470 (or 470F if needing wireless capabilities)
- VR61 wiring centre giving you hot water priortiy + 2 heating zones
- Use only one zone for rads and then connect the UFH circut as in the doucment (AIUFH2.pdf) and use your own controls if needed that came with UFH system"

What I understood is, that if I dont want to use Vaillant controls for the UFH, then I dont need VR81 (as you used) as 470F will act as one thermostat and I can then use whatever stats I got with my UFH system.

Does the above sound right to you?
Hi Capri,

Yes, that sounds correct to me.

I decided I wanted to use the VR81 as I liked the idea of using all Vaillant controls. I can see and set the temperature of the VR81 from the VRC 430, not that this is a big deal, but its useful to control everything from a single point.

Replacing the VR81 with your own thermostat to control the UFH is definitely doable.
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btw, can it be reversed? is the main controller VRC 470 controlling the UFH and VR81 controlling the CH?
I can't say for sure that this is possible as I don't have this setup and haven't tried it, but it does appear other people are using the VR81 to control CH and the VRC 430 (or the later model that you have) to control UFH.

My understanding is that it is simply a setup issue and you associate the VR81 with the zone when programming the system, but I'm not 100% sure about this.

If you search the forum you should find examples. Here's one:


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