1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

VR 10 and VR 11 probes with Vaillant VR 71 Wiring Centre

Discussion in 'Plumbing and Central Heating' started by Milleniumaire, 9 Sep 2020.

  1. Milleniumaire

    Milleniumaire

    Joined:
    7 Jan 2010
    Messages:
    603
    Thanks Received:
    6
    Location:
    Yorkshire
    Country:
    United Kingdom
    Although I bought a Vaillant VR 71/VRC 700/VR 91/VR 91 pack earlier this year, I've only just got around to opening the boxes to look at the goodies inside, since I'm almost at the point of getting my heating engineer in to do some work on my system.

    The VR 71 wiring centre comes with 4 x VR 10 probes and 1 x VR 11 probe. I've had a quick look at the system diagrams that are provided and it appears that the VR 10's are connected along with each valve. My current VR 61 has no such connectors for VR 10 probes, only for the valves.

    I believe the VR 10 is a temperature probe, but I'm not sure. I assume the VR 11 is the same! What is the difference between the VR 10 and VR 11?

    What is the purpose of these probes? I'm not really seeing a use for them in my existing system that comprises of DHW + UFH zone + CH zone (soon to include a second UFH, hence the upgrade from VR 61 to VR 71, with related controls).

    Thanks.
     
  2. Sponsored Links
  3. Milleniumaire

    Milleniumaire

    Joined:
    7 Jan 2010
    Messages:
    603
    Thanks Received:
    6
    Location:
    Yorkshire
    Country:
    United Kingdom
    To answer my own question, it turns out the VR 10 sensors are VERY important and MUST be connected to the VR 71 wiring centre otherwise the system doesn't work. My Vaillant engineer found this out while installing the new VR 71. Initially he didn't use the sensors, then called Vaillant who told him they MUST be connected. The sensors have to be wired up to each zone connection on the VR 71 and the probes attached to the relevant flow pipes for each zone. In my setup, a sensor should also be connected to the new LLH flow, but the engineer didn't do this! The system works without it and I only spotted this when querying Vaillant about how their schematics didn't match my system. Eventually, they supplied me with a schematic which was very similar and this allowed me to confirm exactly how it has been setup by the heating engineer. There were a few settings on the VRC700 controller that weren't correct also! To quote my installer "Vaillant have made this system far too complicated"!

    Obviously these sensors are being used to measure flow temperatures for each zone, however, I'm unsure exactly what impact this has on the way the system works.

    In the early days I struggled to get the house to warm up and reach the desired 21 degrees C set on the VRC700. After lots of experimentation and questions to Vaillant it now appears to be working okay, although I'm now having to use a higher heat curve than when the old VRC 430 was used and prior to the LLH. I also worry about the lack of condensing as the temperatures of the flow return between boiler and LLH (primary circuit?) are always very high and very close together!
     
    • Thanks Thanks x 1
  4. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page