How does the Tado TRVs act when changing temperature slightly?

edited October 2020 in General Questions & Topics

We're looking to get a smart heating system, but before we can choose, I have a pretty... Strange question, maybe.

And sorry if I'm not super clear, I'm not 100% sure if I'm using the correct terms in English.

In our home, we have direct cycle district heating (with direct cycle, I mean that we have no heat exchanger, i.e. the water in the actual radiators comes directly from the heating company), and the pressure is rather high, which makes fully open valves hiss quite a bit.

For old-fashioned thermostatic radiator valves, that is not really an issue. The flow opens and closes very slowly, so if it is a little bit too cold, you'll not really notice any hiss.

However, we have some semi-smart HomeXpert valves, and they work... Different. If it needs to adjust the heat a bit, the valve is fully opened, and when the temperature is reached, it's fully closed again. Which would be fine, if it wasn't for the hiss from the fully open valves. When the temperature needs to be raised in the morning, everyone wakes up. Not ideal.

So my question is, how does the Tado valves do it? Slow "traditional" TRV-like control, or the same yanking the valve fully open as the HomeXpert valves?

And if it does yank it open, and anyone else has the same hissing issue as us, did you find any workarounds?


Best Answer


  • i have the same question.

    Today i've added 8 additional Tado trv's & i've noticed the rad in my daughters room is hotter but i'm not sure if that is just because its got a bit colder and vsmart is running higher flow temps. Rooms are over heating too. Will see in a few days if the trv's will modulate instead of on/off.

  • In my experience - but I'm not 100% sure about it - Tado has 2 settings: 100% open and half open (or at least 'less than 100%'). So sometimes they - like you said - yank open fully and the room heats up quickly, but they are a bit more subtle than the semi-smart ones you describe; they do also sometimes stay close to the desired level, opening a bit and closing a bit. I'm not sure how refined they are, as in 'how many gradual steps they have'.

    Maybe someone else knows that?

  • LosD
    edited October 2020

    I talked to support about it, and while it does have multiple levels (as @guimers8 suggested), they pointed to a problem no matter what: Going back to day mode is usually quite a large change, regulation-wise. It will open up fully. I don't know why I considered it a small change.

    Unfortunately, there is no way to limit how much the system opens the valve, so until we get it converted to indirect (or whatever the name is for a modern system with a secondary loop inside the home), we'll probably have to wait.

    By the way, extra props to Tado's support for giving it to me as it is. No sugar coating or trying to convince me to use their system, instead a good description of how it works, and an honest "If you want to avoid the radiator hissing, we cannot recommend our Smart Radiator Thermostats.".