How do wired thermostat and Tvr work together

I have a wired thermostat and was thinking of getting the radiator valves to go in other rooms.
My question is, if the wired thermostat is not calling for heat as in off but the radiator valve want heat does the boiler come on and just heat that room. Or does the room thermostat have to be calling for heat for the radiator to get heat?
Hope that makes sense


  • johnnyp78
    johnnyp78 ✭✭✭
    The Tado trvs can call for heat. Any room with radiators without trvs will also get heated though.
  • I don't have Tado at the moment currently using a Hive which I am swapping to Tado (EU version as I want ebus connection to my Vaillant boiler also will be adding TRV's I believe the thermostat or TRV's can call for heat.

    Which ever TRV calls for heat that room will warm up only not all the radiators each TRV will have its own temperature for that room basically turns into a zoned system.

  • johnnyp78
    johnnyp78 ✭✭✭
    @vmguru that’s not quite right. No matter how many devices are inside, each room has one measuring device, either one trv or thermostat, that gives the temperature for the room and calls for heat. That’s what sets the room temperature.
  • A follow up question, as I have a new Tado setup but no TSVs yet. Will the TSVs continue to call for heat if their temperature goal is higher than the temperature goal of the main Tado thermostat? Is it even possible to set the temperature on the TSV higher than the main thermostat? Or are they basically completely independent of the main thermostat?
  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited February 2

    @Reezle there are 3 modes of operation:

    1) A TRV can call for heat regardless of the temp/schedule set for the main thermostat (zone controller). So, yes the temperature on the TRV can be higher than the main thermostat.

    2) A TRV cannot call for heat and operates independently without a zone controller. The TRV has its own temp/schedule, but will only heat the radiator if the main thermostat is calling for heat. In effect the TRV controls the maximum temperature in the room, but not the minimum temperature.

    3) A TRV can be grouped with the main thermostat in the same room, using the same schedule. The main thermostat measures the room temperature and commands the TRV to switch the radiator on/off,

  • Thanks for the replies, think I understand now I was just confused by the fact the tvr’s don’t have the ability to turn on or off the boiler only the thermostat can do that ? So if the thermostat is off how can the Tvr call for heat?
  • Please read the reply from @GrilledCheese2 again.......

  • Grilledcheese2

    This is all very frustrating.

    It appears that the TRVs which I have on most radiators apart from the Lounge (which is contolled by Room Thermostat) can call for heat and effectively overide the Room Thermostat; the Lounge (and other non TRV areas*) which get a roasting beyond their set temperature. The room thermostat is not shutting off at its programmed temperature. If it did then the TRVs would not reach their temperature.

    It would be appear that I need a TRV in my Lounge to ensure it cuts off its radiator correctly. Am I right?

    • *I have one radiator which is not TRV controlled because it was set so that ordinary Manual set TRVs can't shut the system off, a safety measure.
    • Thanks for any help.
  • Yes, installing a smart TRV in the lounge will stop the room from overheating. The combination of wall thermostat and TRV will give you good temperature control.