OpenTherm Max Flow Temperature setting


Each time I want to change the max water temperature settings of my heating system, I have to email tado. This takes time (usually a few days!), and also eats resources at tado's side.

I would like to have an advanced settings menu made available, where I can access these settings myself.

It will be benificial to both end users, and tado. Plus you could keep these settings hidden for less experienced/capable customers.

24 votes

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  • This is for me is a non negotiable change that absolutely has to happen, I'm a heating engineer of 25 years and even the cheapest open therm devices on the market such as EPH combi pack 4 has a function to set and limit the maximum heating flow temperature.
    Running a condensing boiler at 80 degrees is madness.

    ALL new boilers have been condensing type for the last 15 years and it's part of their fundamental design to run on a slightly lower flow temperature.

    It's absolute no brainer and without this function it's a deal breaker for us to be able to specify this our customers and we install over 200 hundred boilers a year.
  • Agree! Same problem here!
  • Hello, I am having the same issue, is it possible to ask Tado assistance to reduce remotely the MAX temp? My condensing heating system is overheating at 80C!!! Thanks
  • @Asbesto

    Changing the setting remotely is not the problem. Just e-mail/chat with them. This can take a few days because the first line support can’t do much.

    My request is to allow users to change the settings >themselves<.

    Same thing goes for the PID temperature control strategy by the way…..

    I have to email support, wait a few days for a short reply that doesn’t anwer all of my questions, mail again……

    Tado: Just make an advanced user menu! Allow people access to the full features of their expensive devices.
  • Totally agreed! They decreased remotely my temperature, however we want an advanced menu
  • I do this by configuring the max flow temp on the boiler itself to 60 deg in deep winter and 55 otherwise, but agree having this in the app would be awesome.
  • This would be a great feature and should be very simple to do (probably save more time on the help desks than the engineers would take to implement it!).

    Don't suppose anyone has had any updates on this feature?
  • lll

    Ideally Tado should be smart-enough to automatically compute 'optimal max temp' based on the data like outisde temp, forecast, desired temp, heating schedule, etc - similar to how temp curves can be adjusted on the boilers.

    I posted the following as a new feature request, but it got deleted, likely because it is kind of a duplicate of this request, so pasting it again here:

    When Tado controller operates in OpenTherm or similar mode, it has got full autonomy over flow temperature / modulation of the boiler - from my experience, it is not possible to override these in any way from within the boiler configuration, you are at mercy of what Tado dictates (at least this is the case in Viessman boilers).

    Unfrotuatenly, the logic is not ideal - when the thermostat calls for heat, Tado will ramp up flow temp to the absolute maximum permitted by the boiler (usualy over 80C). It will stay in this mode potentially for hours (especially in a big houses), until the rooms are close to the desired temperautre - and only then flow temp is gradually reduced to a more sensible levels.

    I am sure this is done to make sure rooms gets heated up as soon as possible, but is also a problem, since in a modern condensing boilers combustion efficiency is directly related to the heating flow temp (lower temp = higher efficency):

    This means boiler for a significant amount of time operates at only ~ 87% efficency, instead of potentially 98% or more - which directly translates to higer gas bills (and enviroment impact), quite important aspect, especially in the current global warming and cost-of-living-crisis climate.

    To solve the problem, generally boilers allow to control 'temperature curve' - so max flow temp is limited based on the temperature outside (the logic is that there is no point blasing the flow temp to the max if the difference between indoor vs outdoor is only a few deg C or so - much lower temp will do the trick too, while achieving higher combustion efficency). For example:

    However, the above logic does not seem to work when Tado is in charge of boiler parameters via OpenTherm.

    I don't really think full manual curve control is needed in case of Tado - it feels like the system has got all the information (outisde temp - including forecast, all the internal temperatures, desired temps schedule, etc) to make 'smarter' flow temperature decisions.

    In OpenTherm and similar modes, it would be great to have an option to either 'prioritize heating performance' (basically the current behaviour using max flow temp possible when ramping up) or 'prioritize heating efficency', which would automatically reduce max flow temp based on the env factors mentioned earlier, to maximize benefits of condensing mode and improve combustion efficency (at the expense of rooms taking a bit longer to heat up)

    Implementing such 'efficency' option should be relatively straightforward - and could also be a great marketing story in these troubling and difficult times, when global warming runs unchecked, heating costs spiral completely out of control and many families struggle to pay the bills...

  • Yes I couldn’t agree more. I keep wondering if I should install the Viessmann weather /temp compensator and let the boiler do the temp calculations and turn Tado into a less smart ‘switch’ to start and stop the boiler for each room depending on of it needs heating or not.
  • Thanks @lll for describing it so succinctly, I think your suggestion is the right definition of what smart heating system should be doing. I also questioned myself why when heating is requested it normally uses the max flow temperature in the beginning even if the temperature difference is small.

    I would definitely choose a 'prioritize heating efficency' at all times since my boiler is also a condensing one.

    Let's hope Tado make the smart system 'smarter'.