Non-SRV radiators getting heat when they shouldn't be.

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kettykrueger
kettykrueger ✭
in General Questions & Topics

Hi

I'm having an issue in my home, which has a wireless starter kit, and 7 Tado smart radiator valves (4 other radiators in the house don't have SRVs). My boiler is an Ideal Vogue C32 Gen 2.

Whenever heat is called by any SRV, the radiators that don't have SRVs are also heated, even though they are in separate rooms. As I understand it, radiators without a SRV will be heated as per the temperature and schedule Wireless Thermostat?

I've raised a ticket with customer service but no reply yet, so was hoping to get some help from here.

Thanks in advance.

Answers

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
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    Radiators without a smart TRV will heat up whenever the boiler turns on. In a single zone system there is a single pipe taking hot water from the boiler to ALL of the radiators. The smart TRVs can turn the water supply to a radiator on and off. Radiators without a smart TRV will continue to heat until the temperature on the manually controlled TRV head is reached.

  • kettykrueger
    kettykrueger ✭
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    Hi

    Thanks a lot for the reply.

    So I’m my case, what’s the point of the wireless thermostat, if it’s not controlling the temperature in the rooms without SRVs?

    Is the only workaround to put SRVs on all radiators? If so, that won’t be possible in my house as I have 11 radiators and I believe the limit for Tado is 10.

    Cheers
  • GrilledCheese2
    GrilledCheese2 ✭✭✭
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    The wall thermostat can measure the temperature of a room and call for heat if a room is below the required temperature. Alternatively you can group the wall thermostat with one of the smart TRVs. Of the two devices in the group the wall thermostat will be the only temperature sensor, and the smart TRV will simply respond to requests to open/close the radiator valve. This second option will give you more accurate control of the room's temperature (temperature sensors next to a hot radiator are rarely accurate).

    The limit of 10 devices only applies to smart TRVs when they are configured to "request heat" from the boiler. There's a second configuration where the smart TRVs are "independent". An independent TRV cannot request heat, but will regulate the maximum room temperature according to the schedule.

    Depending on your heating system it may not be possible to put a TRV on every radiator. Sometimes one radiator has to left with no TRV, so there is always a radiator for hot water to flow through.

  • kettykrueger
    kettykrueger ✭
    edited November 2022
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    Again, many thanks for the reply.

    Just to add to this, I've just come home, where the only radiator that should be on is the living room (and non SRV radiators) but my kitchen radiator (with Tado SRV) is also on, and so is the one of the bedrooms (which also has a Tado SRV). Neither of these radiators should be on according to the schedule (I also don't have 'early start' enabled).

    This has now been resolved by re-calibrating the SRV.

    Also, when you said that one radiator needs to be left with no TRV, why is that? The hot water comes from the combination boiler 'on demand' so not sure what you mean.

    Finally, you say the limit for SRVs that call for heat is 10, does that include SRVs that have been grouped? https://support.tado.com/en/articles/3752262-how-many-rooms-and-devices-can-i-have-in-my-tado-home This link doesn't appear to be clear on the situation.

    Thanks :)

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited November 2022
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    Your boiler has a metal heat exchanger that transfers heat from the gas burner to the water. The boiler relies on a flow of water through the heat exchanger to work properly. If the water stops flowing the heat exchanger becomes a kettle as the same volume of water is repeatedly heated. When water boils it expands to form steam and the extra pressure can damage the boiler.

    In recent years a bypass valve is fitted inside or outside the boiler to ensure the water can always flow. In the past one of the radiators was used to provide the bypass. If you already have TRVs on every radiator then it should mean that a plumber has previously fitted a bypass valve somewhere.

    If you have multiple SRVs in a room, then I'm pretty sure that only one device counts. So 10 rooms, rather than 10 devices

  • kettykrueger
    kettykrueger ✭
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    That's great, thank you for all the help.

    I posted earlier about some radiators with SRVs turning on when they shouldn't but I resolved it by re-calibrating the SRV. Well, that's no longer the case!! I have 2 radiators (with SRVs) coming on whenever the boiler is on.

    Any ideas how to resolve this?

    Thanks

  • kettykrueger
    kettykrueger ✭
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    @GrayDav4276

    Thanks for reply. I have just checked that and the correct Zone Controller is set (they are not independent).

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited November 2022
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    @kettykrueger try swapping the 2 two problematic TRVs with 2 TRVs that you know to be good. Don't change anything in the app, just move the TRVs. If the same radiators are heating up when they shouldn't, then it indicates any issue with TRV valve connected to those radiators. If the problem moves with the TRVs to different radiators then it potentially means you have a problem with those Tado TRV heads.

  • kettykrueger
    kettykrueger ✭
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    @GrilledCheese2 Thank you. I was able to swap two SRVs over and the problem persisted so it sounds like a problem with the radiator. Could it be that an adapter is needed?
  • Kissarmy
    Kissarmy ✭✭
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    It could be that the springbloaded pin is sticking. If there is a lot of resistance the Tado valve might not manage to fully close it while calibrating. Take the Tado valve off and use something blunt and metal such as the handle of a spoon and try depressing the spring pin a few times to loosen it up.
  • kettykrueger
    kettykrueger ✭
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    @Kissarmy Thanks. So I tried that and it did more resistant to move than others. I’ve tried depressing it a few times but it’s still stiff. Could I try some WD40?
  • eezytiger
    eezytiger ✭✭✭
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    WD40 is not a permanent lubricant. It evaporates. It is good to free tight things initially, but does nothing long term. For example, you could use it to clean a bike chain, but never to lubricate it. Try regular engine oil (clean), 3-in-1 oil or even olive oil.

  • Kissarmy
    Kissarmy ✭✭
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    I would go with @eezytiger suggestion. If you have the orhiginal dumb TRV head - or can borrow one off a different radiator they can be good for opening and closing the pin a lot of times while the oil does its magic.
  • Robv
    Robv ✭
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    @kettykrueger was this issue solved, I'm also having the same problem what particular radiator is coming on when our wireless thermostat is calling for heat rather than the SRV on the radiator its self
  • kettykrueger
    kettykrueger ✭
    edited January 2023
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    Yeah I did. I tried the suggestions above (loosening the pin) but they didn’t work. In the end I bought some new valves from Screwfix and replaced them.

    Luckily, my father-in-law is a plumber so he changed them for me. They’ve been perfect since.

    I think they cost £8.
  • Robv
    Robv ✭
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    Thanks, any idea what they were specifically called no problem if not
  • kettykrueger
    kettykrueger ✭
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    Hi

    Yeah, it was this: https://www.screwfix.com/p/white-angled-thermostatic-trv-15mm-x-1-2-/60368

    Obviously, the thermostat is redundant but not sure if you can buy the valve with it?

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