In what steps can the radiator valve regulate heat? And for the thermostat?

So what I'd like to know:

  • In what states can the radiator valves be? Is it fully open, half open, closed? Or are there different options
  • What do the three wavy lines mean? Do they correspond to the valve states or to the required power from the heater?

I'm trying to better understand how tado works to optimize my own setup, so some insights here would surely help.

Best Answer

  • GrayDav4276
    GrayDav4276 ✭✭✭
    Answer ✓

    Hi @Schippie ,

    This question has been answered very is the "Definite" answer as supplied by Tado Support........

    ## UPDATE ##

    Hi Everyone,

    I have now had the "definite" response from Tado Support regarding how the Tado SRT's operate the TRV's on our radiators......

    The SRT only "fully opens" or "fully closes" the TRV valve. It does not "partially open" the valve if 1 Wavy Line is showing........or........"increase opening level" for 2 or 3 Wavy Lines

    The Wavy Lines are an "illustration" of the level of "demand" applied to your boiler......So

    1 Wavy Line = Light Demand (which could be just the pump operating and no boiler firing)

    2 Wavy Lines = Medium Demand

    3 Wavy Lines = High Demand

    Also.......if the difference in temperature demand is more than 1 degree then the boiler demand will be Medium or High (dependant on the size of temperature differential.....2 or more degrees) So I 'step' my change in temperature (in the App etc) in in 1 degree increments (SRT) and 0.3 degrees (Wireless Thermostat).......this reduces the "High Demand" on my boiler (modulating boiler)

    It was a bit of a "faff" to change my schedules......but I feel that it was worth it.

    There will be people who don't like to have this level of interaction with their Smart CH system, and so this will not be for them......and I appreciate that. There will also be people who may have already known all this.......respect.

    But there will be many people who didn't understand how their system "actually" works, and have had a "skewed" perception of what is/was happening.

    And so if I've helped anyone.......I'm happy .......if I've annoyed anyone, then at least you've read this post.

    Hey @Schippie ,

    I can supply the text from the Tado Support email if you still have doubts.......but I'm telling you the facts......and not just my own opinion.



  • Schippie
    Schippie ✭✭✭
    Thanks. I believe you of course @GrayDav4276. I just hoped someone would give a more palatable answer. I find it so hard to believe Tado would only allow open and closed. On the face of it, it seems incredibly dumb to not implement more fine grained control. On the other hand, it’s not as if the algorithm would be able to take advantage of it 😉. Still weird though.
  • cbd20
    cbd20 ✭✭✭
    That's interesting and not actually what I thought was happening. You've got the information straight from Tado so it must be true, however it does seem to conflict with what I "hear" my radiator thermostats doing if that makes sense.

    If I listen to my Tado TRVs the motor definitely runs for different amounts of time depending on circumstances.

    For example, first thing in the morning when the schedule kicks in and the room is cold, the one in the bedroom opens and the motor runs for a good couple of seconds as it does so. As the room starts to warm up I can hear the radiator thermostat make small adjustments, i.e the motor only runs for a fraction of a second. Checking the app as it does this I can see the heat request percentage change for that room.

    Now I guess potentially it could be fully opening and closing several times over the period, but the duration of the motor noise is definitely different. Hence my assumption that they could partially open. I guess my assumption was wrong.
  • Hi @cbd20,
    It sounds bad for me to say this.....but....just because Tado Support say something, doesn't actually make it so.

    However to say that it only "Fully Opens and Fully Closes" is actually denegating their own system if they actually "Partially Open" dependant on the temperate setting/achieved.

    I have to admit that I also 'hear' the valve operate for shorter times than you would expect for a "Full Opening or Full Closure" of the valve.

    So although I have received the "DEFINITIVE" response from Tado Support........I'm still not 100% convinced.
  • Schippie
    Schippie ✭✭✭
    Just to be sure, I asked customer service as well. Let’s see
  • @Schippie
    Great idea.....I await your response with Tado's reply........✍️🤷‍♂️😎
  • Schippie
    Schippie ✭✭✭

    Well, I still have questions outstanding from January 2nd, so it might take a while.

  • @Schippie ,

    I'm assuming you mean Tado Support....??🤔

  • Schippie
    Schippie ✭✭✭
    Jup indeed 😉. I have actually asked several questions, none of which are answered yet
  • Be patient.....but don't hold your's a bit dangerous.... LOL 😂
    I had to ask for updates....that seemed to prompt them along.
  • Schippie
    Schippie ✭✭✭

    I made the mistake of not logging the ticket ID's + dates for all my questions, so I can't even realistically ask for updates.

  • I've just asked Tado Support about another issue regarding the operation of my Wireless Thermostat.....let's see who gets a reply first........🤔😎🤞
  • Klaus_Ludwig
    Klaus_Ludwig ✭✭
    edited February 10

    I have done a couple of operational checks on my system, deliberately targetting those radiators that were at the time indicating what I take to be a partial "demand percentage" under Care and Protect.

    I step dropped the set point to well below actual temperature on a couple that were showing less than 20% demand. Both times I heard the motor operate for significantly less time than it takes for the valve to fully open or full close and the "demand percentage" immediately dropped and disappeared.

    However, I did later observe that frequently changing the set point does not always elicit an immediate response from the valve actuator motor though there is a reasonably quick response on the indicated demand percentage.

    From what I can see, contrary to what has been quoted from Tado, the valves do partially open, and are not just fully open or fully shut, but there appears to be a control limit on the valve reposition timing, which makes sense from a battery conservation point of view.

    In my very basic set up I have no variable demand signal linking my Tado to my boiler. If my radiators put out more heat then my boiler modulates accordingly. My radiators put out more heat when the flow through them increases. If the wavy lines change, then indeed demand is changing, but control on my system happens when the valves move. If there is demand there must logically be control.

    I would be interested to hear what Tado has to say on this.

  • Hi @Klaus_Ludwig,
    I would like to hear from someone else at Tado regarding this.....cos I'm not sure if I believe what I've been told.
  • I too anticipate a further answer to this question. sometimes its a long burst of sound from the trv like first thing in the morning when the schedule calls for several degrees increase & other times it's short bursts like when its trying to maintain temp. open a door in the current minus outside temps and the valve in that room will shut with a long sound of the trv motor working, once the timer expires another long burst to open and deliver heat then shorter bursts as the room gets back to temp and the trv prevents the room from over heating.

    the potential for over heating seems too great if these devices are just on/off, but I'm no expert..

  • tadouser1000
    tadouser1000 ✭✭
    edited February 11
    Agree with the comments here about short/long motor noise from TRVs. I've noticed a strong correlation between short motor sounds from TRV and cooler radiator vs long sound and hot radiator (my boiler is running in relay mode so water temperature is constant)
  • Schippie
    Schippie ✭✭✭
    edited February 18
    So I asked the question on chat, and Jurian from tado answered (he’s been quite active on the forum too). He says the tado radiator valve engine can open/close in steps of 5%.
  • samd
    samd ✭✭✭

    @Schippie Great - well done. I suppose it follows that they can open/close in multiples of 5%

  • Hi @Schippie & @samd ,

    If this is correct.....and I hope that it is.....then why did I receive a reply from someone in Tado support to say that the SRT only allowed the TRV to be " FULLY OPEN or FULLY CLOSED "

    This type of discrepancy does not fill me with any level of confidence in ANY Tado Support fact it's diabolical IMHO

  • There should be a faq including details like this otherwise it’s just myth.

  • Schippie
    Schippie ✭✭✭
    I just asked for additional clarification given that someone else from tado claimed only 0%/100% was possible.

    I really hope the 5% thing is the actual case, sounds more sensible than open/close only.

    However, my plumber/installation guy also claimed they only open/close.
  • I personally appreciate any efforts that are being made by Jurian and others at Tado to engage with the community. 

    My guess is that there are a limited number of people at Tado who will have a detailed knowledge of absolutely every technical and developmental aspect and also that there may be the occasional error in their responses to the community, but I would prefer open, honest and authentic engagement with the community with the occasional error to no engagement at all.  

    Even though it has now been "confirmed" that the valves step open and closed rather than only fully open or close, we still don’t know if this is by virtue of a timed pulse signal with the only feedback being for full open and full closed or if the actuators use a positioner which relies on a feedback signal (eg from a potentiometer or proximity sensor) to accurately postion the valve according to a controller signal output. Noted that the percentages on my Care & Protect page are frequently not in steps of 5%, but that would appear to be demand rather than valve position… I had originally assumed it was the latter.

  • Hi @Klaus_Ludwig

    Your comment regarding the readings shown in the "Care & Protect" page are correct the %'s shown are not in 5% graduations, my observations of my "Care & Protect" page bear out your assumption that these figures are more likely to represent "heat demand" and are not an indication of the valve opening. That all makes sense to me.

    It would have been great if someone from Tado could find out the correct answers before blurting out random rubbish.......I'm just not sure if we are in contact with Tado engineers/techies/programmers etc or simply a "call centre" type of responder.

  • Hi @GrayDav4276,

    I agree with your sentiment. It would indeed be good if we could have occasional ad-hoc “official” tech oriented updates/clarifications from Tado for those of us who are interested in more detail. There is a fair degree of speculation and some frustration evident on the forum…

    I am gradually learning more about Tado as time goes on. I see that the company was founded by a few “whizz kids” in 2011 and that in 2017 a “seasoned” CEO was bought in who has experience of scaling up companies. One of their favourite sound bites seems to be that the management are keen on Tado being Hardware Agnostic.

    We are probably relatively early adopters in the scheme of things. There is significant growth potential for Tado if they get it right and I suspect that any company that is growing at any pace may experience some issues including the customer service type. 

    You can be sure that the senior Tado management will be glancing through this forum from time to time even though they are highly unlikely to engage as this is not their level.

  • Schippie
    Schippie ✭✭✭

    Hi guys, as I said before I asked Jurian from tado to confirm that the smart radiator valves really offer more control over the hot water flow than open/closed. His answer (translated of course ;-): the tado valves modulate from 0% to 100% in 5% steps.

    Seems clear enough to me.

  • GrayDav4276
    GrayDav4276 ✭✭✭
    edited February 19
    Hi @Schippie,

    So..... what would an incremental change of 5% actually look like ?? 🤔
    I know that a new SRT "calibrates".....but are we saying that it can detect the actual "workable range" of it's specifically attached TRV valve ?? 🤔 (usually done with no "heat demand" for it's TRV)
    I'm not really convinced.....tbh

    I know I'm cynical but I operate under the context of "just because someone says something doesn't mean it's true"
  • Schippie
    Schippie ✭✭✭

    Hi @GrayDav4276 interesting points. I do know that calibrating involves fully opening and closing, maybe that will serve as the 0% / 100% markers? Anyway, might be a good idea if you could try asking customer service too.

  • cbd20
    cbd20 ✭✭✭
    I suspect that while the tado valve motor has the ability to move in 5% increments, that won't manifest itself as a 5% step on the actual valve pin.

    The calibration is probably just to find the end stops - i.e how many of its 5% "steps" it needs to get from fully open to fully closed. On some valves it may be fully closed before the tado motor has reached its full extent (and arguably that's probably what you want to ensure the valve is definitely closed).

    Either way, the answer would suggest that the tado valve does allow partially open, which is what we all suspected. It just may be that the scale varies for different models of valve.
  • GrayDav4276
    GrayDav4276 ✭✭✭
    edited February 19
    Hey @Schippie,
    If you remember......I've already done that and posted the results earlier in this thread.
    I've also deleted some content of my earlier post today....... cos I was talking bo####ks.....the video that I mentioned was on "lock shields" and not TRV bodies....🤣..... oooooops
  • Schippie
    Schippie ✭✭✭

    Oooh you’re right of course @GrayDav4276, forgot indeed.