Why are my traditional TRVs not working well with TADO setup

I got a registered TADO installer to set up my new TADO wireless thermostat system. I now have 3 rooms where I have 4 new TADO Smart TRVs installed in areas where I need to tweak the settings regularly. They work really well through the app.

I still use traditional Drayton TRVs in all other rooms and the wireless thermostat is in my lounge. These radiators now stay on whenever the boiler is in use meaning they also come on when I don’t want them on as the TADO set up has back to back temperature settings for each time block. Even worse, although the set temperature for the room on the thermostat could be 16 degrees at any particular time, the radiators keep heating beyond that and the sensor can show 22 degrees!! Turning down the TRV doesn’t seem to have any affect. I assume that is because there are no time blocks when the heating is off?

Do I have to just keep adjusting the Drayton TRVs? My old Drayton wireless thermostat seems a dream compared to this. The rads just came on for specific set time blocks. I’m having to go around and turn off all the old TRVs in every room once they are up to temperature. At night, I’m having to put them on to frost protection mode or turn off every room on the app.

Running TADO is costing me more than my old system. Can anyone offer any advice other than installing new smart valves in every room?

Any feedback appreciated!!!

Best Answers

  • Phillip_PAL
    Phillip_PAL ✭✭
    Answer ✓
    There is something wrong with the installation if the room thermostat and other tado trvs are no longer calling for heat but the boiler is still endlessly firing.

    But then you also mention having to constantly adjust the manual trvs surely they should be set and forget regardless of boiler stopping on that's the original purpose of the manual trv that it auto shuts off that specific radiator as it reaches temperature so they shouldn't overheat.

    Note when boiler shuts off / trv shuts off your radiators won't instantly go cold - depending on efficiency and age of radiators they may take 30 minutes or so to gradually cool - particularly if you have boiler set to very hot temperature.

    Your tado schedules should be a lower setback temperature overnight so it's effectively off unless it's really cold - I use approx 18 early morning in living room, 19 during day, 20 in evening, 19 late evening and 16 overnight. This ensures the overnight temperature does not drop too far on really cold nights. Other rooms are similar but a degree or so cooler.

    The remaining rooms on manual trv don't need reducing overnight as the boiler will only lightly heat when essential to maintain those lower temperatures - unless your system is poorly balanced.
  • Phillip_PAL
    Phillip_PAL ✭✭
    edited March 13 Answer ✓
    Ah yes sorry didn't spot you had wireless Drayton TRV.

    Perhaps you may be able to somehow power the old Drayton controller such that it still automates those TRV but can't actually call for heat so only heats if tado already heating elsewhere.

    Essentially that would be the equivalent of setting the tado room to 'independent'.

    For the Tado TRV yes the temperature on those can be temperamental.

    You could try and mount horizontally by altering the plumbing by remounting the valve itself assuming the valve is bidirectional most modern are that moves the trv slightly further away from radiator.

    However best thing is to get a separate wireless tado wall stat but they are expensive- keep an eye out for occasional deals to get at slightly better price.

    I've slowly expanded the tado system over the years.
  • wateroakley
    wateroakley ✭✭✭
    Answer ✓

    @Winnie Changing to Tado TRV/stat (and two rooms with a manual TRV) took us a few months to work out what worked well (see the charts). Having two control systems is always going to be complicated, especially with varying room use. We tried making manual interventions with the old controls and TRVs, with limited success, BLUE in the scatter and line charts.

    It's worth persevering with the one system. We only heat rooms at times and temperatures to suit our use, don't heat rooms when they are not in use, time most hot water for an essential morning shower, turn everything off when we go out (geofencing) and try to remember to turn it back on before we return home. The results of daily kWh vs outside temperature (mean CET) are in the diagram. The first two GREEN Tado months are visible above the scatter trendline (100/6.8C - 87/7.9C).

    The only extra we have bought was a second wireless room stat, to make the lounge a more predictable temperature instead of the TRV offset. For the same external temperature (mean CET) and frugal use, we have achieved 32% - 35% overall savings in the first year. The latest three months, Jan/Feb/Mar 2023, are saving 38% - 39%. ROI was less than 7 months at current gas prices.

    Good luck with finding what works for you.

  • davidlyall
    davidlyall ✭✭✭
    Answer ✓

    This is one of the reasons why I think Tado should make a simple radiator valve that has no sensors i.e. just the motorised valve. This would then be paired with a room thermostat to get an accurate reading and control heat demand in the room.

    They went halfway there with the basic TRV but I expect they could produce a much cheaper TRV if it was purely a motorised valve for the radiator

  • mindstorm
    Answer ✓

    I've got a mixed system with 8 Smart TRV and 7 Drayton TRV on the bedrooms/landing etc. I've got most of the Drayton valves set around 2 which should be 15-16 deg. Yes, the dumb TRV's heat during the day while the Tado is keeping those rooms at the set temperature but I drop everything to 14deg at night and that keeps the bedrooms off. Maybe drop your TADO room temp, mine are at 17deg during the day and we're at home.

    It's a modulating boiler so is on quite a lot of the time but the flow is only around 35-40deg as a result.

    We're in a 1920's 4 bed detached with solid walls downstairs (upstairs has been externally insulated) but we've dropped from 23000 to 16000kwh since Tado and reducing temps. 30% of my heating demand is in one downstairs room which has solid walls and north facing........

    • 1 = 10°C
    • 2 = 15°C
    • 3 = 20°C
    • 4 = 25°C
    • 5 = 30°C


  • Hi Philip. Thanks for your suggestions. I don’t think there is anything wrong with the installation - just my understanding of how Tado works! I had set all the night settings to 14 degrees - this is the night setting we normally use.

    Got to the bottom of the rooms without smart TRVs getting too hot in the middle of the night - the radiators were all still set at 20- 22 degrees. At night time, my old Drayton wireless thermostat would switch the heating down to 14 degrees until 7.00 the next morning so no radiators would come on!!!

    To give a bit more background, we live in an end terrace 1907 3 bed Bath stone Victorian House in the most exposed hilly position in Bath. We get hit by horrendous high winds and driving rain which causes high humidity, especially in the rooms at the front of the house!! Pre - Cost of Living crisis, we were using around 17,000 - 19,000 Kw of gas per year - the equivalent of a normal 4-5 bedroom house and can no longer afford this. I have been endlessly going around the house, turning radiators up and down, turning the heating down to the bare minimum, especially in little used rooms. Two of our household work varying shift patterns and I try to ensure the heating is adjusted in their rooms so it is warm when
    they go to bed. It is such a fag endlessly changing the settings.

    Tado seemed to be the ideal solution to this so I have Tado radiator thermostats in the 3 rooms that I have to tweak the settings for most often.

    I’m gradually getting more familiar with how Tado works but the radiator temperatures tend to differ from the room temperature by about 3 degrees. One night Tado thinks it is warmer than it actually is, the next night it swings the other way!! I am constantly adjusting the offset - the weather seems to throw it out constantly depending on whether it is a cold or warmer night.

    I think the only solution will be to put a temperature sensor in each of the 3 rooms affected. Costly solution though!
  • Thanks Philip - sounds like a good idea to just set up the old Drayton controller again but beyond my skills. It’s all becoming a tad too complicated…. I will see what my installer says.

    I did suggest to him that some people say it is better to mount the valves horizontally but he didn’t believe it had much affect.

    I think the simplest solution for me would be to gradually add Tado temperature sensors to the rooms with the Tado smart radiator valves - the sensor would then set the correct temperature? Not an expense I really wanted but I don’t think these radiator valves are reliable enough.

    The 2 main living rooms with Drayton TRVs are never heated overnight any longer unless it is a very cold night - the old Drayton controller was always set to 14 degrees over night which is generally the lowest the temperature gets.

    If it’s going to be very cold (as predicted for tomorrow) then I can just turn the old TRVs down so they don’t blast the heat out with no one in the rooms to benefit!!! The lounge also has an enclosed wood burning fire and is always lit on cold nights. It retains the heat well and is still around 19 degrees by morning so I can just turn the TRVs down or off in this room when not needed. We do programme the heat to come back on at 10 pm to warm us up before bed!

    It’s just not as good a system as I expected - the valves should be far more accurate than this and I feel I am being pushed into paying for over priced sensors as a result.
  • Hi @wateroakley . Thank so much for the feedback - we seem to have had similar experiences! We too are trying to be frugal with our use of gas - our 3 bedroom Bath Stone house is such a cold house and difficult to heat. Our consumption of gas used to average between 17,000 - 19,000 kilowatts, especially when working from home during the lockdown years so I had to find a way to reduce our costs by controlling how we heated the house. I have reduced our costs by about 35% already this last year and I’m hoping Tado will make this whole process easier to maintain.

  • Hi @mindstorm

    I think we have had very similar issues. The whole front of my house faces North and we get howling winds and rain so the 2 front rooms are always extremely cold and the radiators with Tado valves don’t reflect the true room temperature. Tweaking the offset settings doesn’t help - sometimes the reading given by my Tado valves is 3 degrees less than my room thermometer but it varies a lot according to the time of the day and whether the sun is shining on the front windows.! I just manually check my little room thermometers in each room and use that as the true gauge of how warm the room is.

    The biggest mistake was to put the TADO valves in the coldest rooms that get the least use - I put them in these to make sure that I could control the heating level according to how they were being used. The two living rooms are the ones that are heated to the highest temperatures using Drayton TRVs and in hindsight, it would have been better to have had the TADOs in these rooms. The main lounge has the TADO heating temperature sensor in it. I am for ever turning these TRVs up and down as needed throughout the day. They are awkward to get to and impossible to view without a torch. I think I will end up gradually putting sensors in each room and the smart radiator valves so I can do it all seamlessly from my phone.

    That’s a low temperature for your flow - my boiler would struggle and be working too hard to get up to temperature at that level. I’ve set ours to 50 degrees as per the recent recommendations given by the Energy Saving Trust. It’s an old well-serviced boiler and seems to work more efficiently at this level.

  • I have also requested a simple valve in the suggestions category . . .

  • Good idea - I hope Tado listen but it will be too late for us!!!