What exactly does the high/ medium /low heat request do?

k1s
k1s

Does anyone understand this support page:

How do I know how often tado° turns my heating system on and off?

https://support.tado.com/en/articles/3478984-how-do-i-know-how-often-tado-turns-my-heating-system-on-and-off

It says it shows:

"heat request symbol as a number of wavy lines with 3 being a high heat request, 2 medium, 1 low..."

Then further down:

"For relay systems, the heating system turns on (100%) or off (0%) completely for specific time cycles based on the heat request. "

Does that mean no high, medium, and low for relay users?

Then further down it says:

"...for digital heating systems (e.g. OpenTherm/eBUS), based on the heat request, the heating system modulates the heat it supplies to reach and maintain a specific temperature..." 


But again no reference to high, medium & low.


What exactly does the high/ medium /low heat request do? ...and what kind of boilers technology does it require? (mine is a Vaillant ecoTec Green iQ 627 (not OpenTherm, afaik)

Best Answer

  • DusanM
    DusanM
    Answer ✓

    Relay control is just on/off. Tado can't control modulation of your boiler. You can do that by setting water temperature directly on your boiler.

    Your boiler is fully compatible with eBUS. There are pins directly on mainbord. Tado will then control the power of your boiler (3 levels or no heat).

Answers

  • Rob2
    Rob2 ✭✭✭

    It seems that it supports eBUS.

    I would advise you to chat with the servicedesk for directions. It may be that you need to connect the thermostat to different connection points on the boiler, or set some option. And you need to change the Tado connections and change an option there as well.

  • The boiler manual shows 2 pins for eBus (not 3):



    Tado's installation instructions say:

    "Please identify the terminal block labeled 24V RT. Connect the wires of the cable to the terminal block RT 24V. Connect the Black and the Grey wires to the two terminals of the terminal block labelled 24V RT. The order in which the two wires are connected is not important. Make sure that there is no bridge between any two of the terminals you connect to."

    ...Which contradicts the boiler manual:

    "Connecting a room temperature control via eBUS

    ▶ Connect the control to the eBUS connection.

    ▶ Bridge the 24 V = RT connection (X100 or X106), if there is not already a bridge."

  • In tado package you will receive 3-wire cable. You will use only two wires.

    Boiler manual is correct: you connect the cable to eBUS connection and bridge RT connection. Cable should be connected to +/- DIGITAL contacts in tado unit. Then in setup D07 mode should be selected.

  • @k1s , Hi , which manual are you using, I can't seem to find your text about the Tado installation instructions in the wired manual. I would like to take a look at your situation.
    From my perspective looking at the photo, connect your thermostat wires to the Ebus +-, leave everything else as is.
    In the tado configuration settings at the thermostat choose D07 for Valiant e-bus. Gif the system some time to learn in
  • It is like DusanM says, who posted the correct answer faster :)
  • k1s
    k1s
    edited January 27

    Thanks for your replies.

    The words and photo above were from the installation instructions I got from Tado (:BP5.1 - Installation - ecoTEC plus .._5-5 + timeSWITCH 150 - ENG.pdf"). My boiler PCB is connections currently look like this:

    The grey wire, connected to the 230V RT block is the switched live. The other end of the grey wire is in a crowded Salus wiring centre, connected to the [orange] call wires for the hot water zone valve and zone valve for radiators [upstairs], and the 'live return' from the [downstairs] underfloor heating manifold (Heatmiser UH4 Wiring Centre).

    As instructed by Tado:

    The Tado wireless receiver CH N.O. is connected to the Live [brown] zone valve for the [upstairs] radiators.

    The Tado wireless receiver black wire HW N.O. is connected to the the cylinder thermostat common

    and

    The Tado wireless receiver CH COM bridged to Supply L (Live);

    The Tado wireless receiver HW COM bridged to CH COM (hence supplied with Live).

    So, I think from answers above I need to connect the wireless receiver "-" and "+" as @DusanM said, like this:

    and bridge the 24V RT connection.

    But what about the existing connections to the zone valves and cylinder. Should I leave them in place?

  • Well, that's more complicated setup 🙂

    Wiring centers you mentioned - are they controlling heating zones by opening/closing valves? Do you have room thermostats that control above wiring centers?

    In any case I would suggest you call proffesional installer who inspect your current setup and choose right installation.

  • @k1s , Tado specifically talks about a 24v RT terminal block thats were you should connect your thermostat wires

    DO NOT connect to 230V,

    You fould correspond your picture to tado with your setup to correspond what to change.
  • @de_bigMaq

    Yes, if only Tado customer support would respond with anything other than "ask an installer".

    Upstairs has 7x Tado "Smart TRVs", and a "Wireless Receiver" (plus one obligatory Tado "Wireless Temperature Sensor", without which, apparently it is impossible for Tado to see/control the hot water).

    The Tado Wireless Receiver is wired into the Salus CT100 wiring centre (essentially a dumb junction box) with the connections mentioned above: CH N.O. to the Live [brown] zone valve for the [upstairs] radiators; HW N.O. to the the cylinder thermostat common (both via another wiring centre/junction box, in another room).

    Downstairs are 4 underfloor heating zones, with Tado "Wired" thermostats (albeit powered by batteries). These are wired to a Heatmiser UH4 wiring centre/circuit board), which essentially sends the call for heat from any of the UFH zones via a single cable to the back via to the Salus wiring centre to the 230v switched live at the boiler.

    The whole thing is currently wired like this:



    Sure, I could get "a professional installer" to come and poke around, but it was a "professional installer" who set this up (all the time saying I should forget about Tado and stick with Vaillant only equipment).

  • @K1s well I can surely feel your professional installer . He knows what would surely work an I guess Tado was not within his expertise.
    Along the way of questions in this discussion we actually get a more complex situation presented of which I would say above my pedigree . And raising more questions, like beside a wireless Tado thermostat with receiver I also notice 4 wired Tado thermostats , I guess they are connected to floor heating but, although I don't have floor heating, why 4 , cause the people I know dont have 4 extra thermostats.
    In your case I would present my wiring scheme to the servicedesk.

    Considering your topic question, the heating stripes represent the heating and opentherm modulation In the relais setting ( on/off) you always see 3 stripes on or off
  • @de_bigMaq Please validate what you are writing. “Considering your topic question, the heating stripes represent the heating and opentherm modulation In the relais setting ( on/off) you always see 3 stripes on or off” is not true, there is something called pulse width modulation used. See this topic (in Dutch).


    @k1s I fully agree with de_bigMaq - this setup is way beyond what we can safely help with, and so is tado support (very rightly they say ‘consult an installer’ - they don’t want to end up in all kinds of legal hassle).

    Basically you are mixing two brands with different philosophies, not guaranteed to work. So, indeed consult an heating expert/installer with sufficient knowledge of all devices you are trying to set up, or I’m afraid you are on your own.

  • @Andreplusplus " Please validate what you are writing......pulse width modulation used" I was only describing when I see 1 or 2 heating waves in the app view looking at a room. For me 3 stripes is when my kettle delivers a 100% heat request from my tadoknob for instance when heating from 16 to 18 degrees. In the final stages the kettle does not need to deliver 100% so the number of heat stripes in my Tado get less and usually only one when it has to hold on to the temp for a long duration. Am I looking at it the wrong way?

  • @de_bigMaq, indeed my app shows 3 different bars, not just all on or off. Yes I have one tado Wired thermostat for each UFH zone. UFH zones are quite common, with manifolds to regulate the flow to each, as needed.

    @Andreplusplus, Thank you for the link to the discussion about pulse width modulation.

    My heating set-up is not exotic or especially complicated. So called "S-Plan" Radiators & hot water upstairs, multizone UFH downstairs is very common.

    I think the stock response 'ask an expert' / [implication 'grown-up'] is not helpful. Yes, of course I am mixing two brands - Tado doesn't make boilers. But they do make controllers for boilers, and as such it is in their interests to provide appropriate technical support for the largest boiler manufacturers in Europe.

    Unfortunately, my experience of Tado support has been characterised by almost banal suggestions, like "have you tried resetting it?". Send us a photo of your wiring, and then effectively - as you appear to be advocating, "ask somebody who knows about this stuff".

    I have indeed asked several heating installation 'experts' (i.e. certified 'Master Heating Installation Engineers", including the one I referred to above. They mostly say, "stick with reputable brands [that we have extensive training with]".

    Sure, I could do that and return the Tado equipment, yet I prefer to try to support the brand we invested in, so here we are on a Tado forum, trying to work out how to get the most out of the equipment we spend some [not insignificant] money on.

    I can't read Dutch, but from Google's translation of the thread, it seems 'Rob' has some relevant knowledge: Among his post he writes about pulse width modulation:

    "How the boiler responds to this is also different. Some do indeed turn on/off. Others 'understand' this control."

    "Pulse width modulation is only used with the relay. With Opentherm, Nefit EMS, Vaillant eBus and all those other digital controls, modulation is done in a more advanced way".

    Indeed I prefer to have the boiler do it in it's "more advanced way", if possible. The challenge appears to be how to wire Tado controlling devices - in this case a it to send it signals via ebus, while also signalling the CH and HW zone valves.

    Having read around a bit here, it seems I need an older Tado Extension Kit (EU version) wired to an older Vaillant VR65. Of course, both these models have been withdrawn from the UK market because each company prefers to try to created a marketing walled garden rather than an open industry standard which allows for more direct competition.

  • @de_bigMaq, indeed my app shows 3 different bars, not just all on or off. Yes I have one tado Wired thermostat for each UFH zone. UFH zones are quite common, with manifolds to regulate the flow to each, as needed.

    @Andreplusplus, Thank you for the link to the discussion about pulse width modulation.

    My heating set-up is not exotic or especially complicated. So called "S-Plan" Radiators & hot water upstairs, multizone UFH downstairs is very common.

    I think the stock response 'ask an expert' / [implication 'grown-up'] is not helpful. Yes, of course I am mixing two brands - Tado doesn't make boilers. But they do make controllers for boilers, and as such it is in their interests to provide appropriate technical support for the largest boiler manufacturers in Europe.

    Unfortunately, my experience of Tado support has been characterised by almost banal suggestions, like "have you tried resetting it?". Send us a photo of your wiring, and then effectively - as you appear to be advocating, "ask somebody who knows about this stuff".

    I have indeed asked several heating installation 'experts' (i.e. certified 'Master Heating Installation Engineers", including the one I referred to above. They mostly say, "stick with reputable brands [that we have extensive training with]".

    Sure, I could do that and return the Tado equipment, yet I prefer to try to support the brand we invested in, so here we are on a Tado forum, trying to work out how to get the most out of the equipment we spend some [not insignificant] money on.

    I can't read Dutch, but from Google's translation of the thread, it seems 'Rob' has some relevant knowledge: Among his post he writes about pulse width modulation:

    "How the boiler responds to this is also different. Some do indeed turn on/off. Others 'understand' this control."

    "Pulse width modulation is only used with the relay. With Opentherm, Nefit EMS, Vaillant eBus and all those other digital controls, modulation is done in a more advanced way".

    Indeed I prefer to have the boiler do it in it's "more advanced way", if possible. The challenge appears to be how to wire a Tado controlling devices - in this case a it to send it signals via ebus, while still allowing control of Radiator, UFH and hot water zone valves.

    Having read around here, it seems I need the older versions of the Tado Extension Kit (or EU version, withdrawn from the UK market), and Vaillant's VR65 box, which sends the eBus signal on to the boiler, and allows S-Plan control of both CH and HW zone valves. I still need to think through how the UFH can be managed. Maybe a separate VR65 for that. Of course, getting hold of them may be difficult as they too have withdrawn them from the UK market as they would prefer a walled garden marketing approach, rather than lose share of the controllers to companies like Tado.

  • Andreplusplus
    Andreplusplus ✭✭✭
    edited January 28

    @k1s YMMV, but “My heating set-up is not exotic or especially complicated.” does not fit with the wiring diagram you showed. @DusanM said so too.

    Simple/regular/common is just 1 thermostat and 1 boiler.

    ”Yes, of course I am mixing two brands - Tado doesn't make boilers.” In your diagram I see three different “wiring centers”, I don’t even know what these are. Passive devices to connect wires? Or active switching too?

    And brands: I see Vaillant Ecotec, Honeywell, Heatmiser, Salus, tado.

    Tado Extension Kit is replaced by tado wireless receiver to my knowledge. (but Idk about UK market).

    “plus one obligatory Tado "Wireless Temperature Sensor", without which, apparently it is impossible for Tado to see/control the hot water” That is an interesting statement. It wouldn’t be worth the money for me. I don’t mess with hot water control. Water temp must be fixed and the boiler just supplies it when there is demand.

    From the wiring diagram I deduce the Wireless Receiver switches mains power. I can’t exctly find out what, but it seems it only opens/closes the two valves on the right of the diagram. But I can’t determine what controls the boiler. And you said it is not “especially complicated”….

  • k1s
    k1s
    edited January 29

    @Andreplusplus

    "In your diagram I see three different “wiring centers”, I don’t even know what these are. Passive devices to connect wires? Or active switching too?"

    If you don't know what they are, then why do you assume [wrongly] that it's complicated? Just because there is a wiring diagram? 'Wiring centres' are generally just junction boxes with screw down terminals to allow various devices to be connected together and served with common live, neutral and earthing points. Such devices are motorised valves, cylinder thermostats, and programmers (or - in your 1970s example - a single thermostat instead of a programmer). All of this is completely standard / simple for installers.

    In my case I have 2 'wiring centres' / junction boxes upstairs because the boiler and cylinder are in different rooms - again not complicated, just means the installer minimised the number of cables he passed through the walls by running 2 multi-core cables through, instead of all the others back and forth. The brand is irrelevant, they're just terminal blocks like this "Honeywell Wiring Centre", to which the 2 Honeywell motorised valves are connected:

    When you have multizone underfloor heating (which some houses do these days), you get another 'wiring centre'. This one is slightly more than a junction box, because it it fused and contains the relays triggering the pump and zone valves for each zone, and connections for a thermostat for each zone. These generally operate to common standards for the versions that use a switched live to communicate with the boiler - like mine - i.e. it also doesn't matter which brand it is - that's just a logo on the box.

    About the hot water - sure if you have a combi boiler, just set the required temp on the boiler, and you're done. With a hot water storage tank, some people do the same, set a max temp on the cylinder thermostat, and let the boiler keep topping up the heat all day/night. I prefer to consume less gas by having a water heating schedule.

    "From the wiring diagram I deduce the Wireless Receiver switches mains power. "

    You deduction is not quite correct. It is supplied with live, and sends a switched live signal to the boiler + motorised valve for the radiators circuit when one of the radiators calls for heat, or to the boiler and when the hot water schedule is 'on'. It's connected to the cylinder thermostat so that the call for heating is stopped when the water in the cylinder is at the maximum temperature. This is also how most wall-mounted / dumb thermostats / clockwork programmers are wired. What surprised me - hence my comment - is for the 'Wireless Receiver' to work, Tado support told me it needs the other component in the kit to also be installed: the "Wireless Temperature Sensor", which is otherwise redundant if there is already a Tado thermostat in the same zone/room.

    As I said, this is not a very complicated or unusual set-up: within the capability any registered/certified boiler-installer; and certainly should not present any confusion for Tado. My difficulty in getting much sensible out of their 'support' is a reflection of the low level of training of their 1st & 2nd line - not the type of installation.

  • @k1s "1970s example". My boiler has a mains plug and 2 wires to a single tado thermostat. Last time I checked the calendar it was 2022...
    The rest I didn't read. Good luck with your heating.