Help! UFH and HW working but no CH.

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richardbaldry
richardbaldry ✭
in General Questions & Topics

Afternoon All,

Over the weekend I installed the following equipment in my parents house and now they have no CH unless I manually open the CH valve and either Hot Water or Underfloor Heating are active.

  1. Wireless Receiver
  2. Internet Bridge
  3. 4no. smart TRV (basic)
  4. 1no. Wireless Temperature Sensor
  5. 1no. Wired smart thermostat connected to UFH.

I have 3no. system valves controlling CH, UFH, and HW all via seperate two port valves.

Hot Water & Underfloor Heating works. Central Heating will not open valve or demand boiler activation.

Zone controller for the CH is set as the wireless receiver from items 3 and 4.

UFH is controlled by item 5

I have locked the CH valve open for the moment so they have CH & UFH but this isnt a long term solution.

Help!

Best Answer

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    Answer ✓
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    If nothing happens when you press the test button then almost certainly a wiring issue. The test button should activate the boiler regardless of the temperature sensor reading and app status.

    You should have CH COM permanently connected to Live. When there is a call for heat the CH NO terminal becomes live which will then activate the 2-port valve. Check that CH NO is connected to the brown wire on the 2-port valve.

Answers

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
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    What did you do with the wires for the previous thermostat that was controlling CH? If they haven't been bridged the wireless receiver won't be able to turn on the CH valve.

  • richardbaldry
    richardbaldry ✭
    edited November 2022
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    Removed / bridged the cables from the previous wireless thermostat controller so they are direct from the Tado Wireless Receiver

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
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    Assuming you pressed the test button on top of the receiver, the heating LED illuminates and you can hear the heating relay click on and off. If this happens and the boiler has not switched on, then I think you have an issue with the CH wiring somewhere.

  • richardbaldry
    richardbaldry ✭
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    Heya, when pressing the test button for CH the led illuminates (and power flashes amber) but nothing happens.
  • richardbaldry
    richardbaldry ✭
    Options

    "Check that CH NO is connected to the brown wire on the 2-port valve."

    This was the winner! Especially when refered to alongside the pro installer docs.

    Many Thanks for your help!

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