Replacing a three channel programmer.

Hi guys...what are my options for replacing a three channel programmer?

Currently I have three zones. Upstairs, downstairs and hot water.

I'd like to replace this with tado and currently have two smart thermostats an extension kit and one internet bridge. I'm aware that the extension kit is only two channel so I'm looking at what else I can do. Tado technical support is non existent and I'm really close to sending it all back.

Would it be possible to replace my 3 channel programmer with the extension kit and use this to run the hot water and the downstairs heating. Also I could rewire the upstairs to skip the programmer and run off the tado thermostat instead...would this work tho? Could I run them off of the one internet bridge??

I had bought some TRVs as well but after reading some of the comments in here about them I think I'm gonna return the lot.

Thanks in advance


  • samd
    samd ✭✭✭

    Just a couple of points from me;

    1. Why are you concerned that a single bridge wouldn't cope with your house? Two floors and hot water is normally no problem. Do you currently have comms problems at home?
    2. Why do you need to re-wire the upstairs? The Boiler control thermostat by default has to be 'calling for heat' for other devices to work but it is an easy switch (chatline - couple of minutes when connected) to make all devices capable of activating the boiler.

    All that said, some of the comments on here concern some missing basic facilities and only you can make the decision facing you!!

  • I am concerned because I'm being told by Tado that it is not compatible. The only option they are offering is to keep my current programmer and use this in conjunction with their thermostats. If I do this I will not be able to control my hot water. As I said I currently use three channels and tado only supports two.

    So in order to get it to work my thinking is to wire the downstairs ch and hw to the extension. After this I would wire the tado thermostat to the existing thermostat upstay but short this at the programmer side.

    I have no idea if the internet bridge can do this as tado technical support refuse to answer the question.
  • samd
    samd ✭✭✭

    Is there something missing here? If you had just asked Tado to give you instructions for your house (2 storey plus HW) they would easily given you instructions pertinent to your boiler. Why do you need 3 channels - is it that you do not intend to Tado your entire system please?

  • Nope, nothing is missing. I do intend to tado my entire house, however tado can only support two channels - I need three.

    I have sent off the details of my heating system to tado but they are unable to help as it requires three channels.

    It requires three channels because when I turn the heat on downstairs the heat upstairs remains off and vice versa. The same with my hot water. To be clear...they are completely different zones. I do not wish to go backwards to one ch zone for the entire upstairs and downstairs as that will not be cost effective it efficient.

    Now...if you know something that I and tado don't know...please enlighten me??
  • samd
    samd ✭✭✭

    OK that clears it up for me. I did not know that you wished to retain 2 heating zones. I just have one heating zone for the whole house and it easily permits efficient heating and remote or programmed switching on\off for each room etc . Each room regardless of which floor it is on, is, in effect, its own zone. I still think I'm missing something - sorry but easily done for me!

  • May I ask how you are controlling each room individually? Do you have tado TRVs installed in each room or something? I can't see how it's possible without them.

    How is this setup and what has made this so easy for you to control?

    Ideally this is the stage that I would like to get to so I'm all ears.

    Please bear in mind that I currently am only using two smart thermostats and one extension kit.
  • samd
    samd ✭✭✭
    edited December 2019

    Yes every radiator has a Tado radstat and some rooms have a couple of radiators each with Tados. In control terms every room (with 1 or more rads) has a smart schedule for the room and every Tado device whether a Wall room thermostat or radstat has full control over the boiler. By default on setting up, Tado have decided that only the boiler-controlling thermostat shall control the boiler but it is easily changed to full device control on the chat line and is done very quickly (once you get through!)

    As a small example, each morning heating comes on in our Kitchen, Bathroom and Bedrooms at slightly different times and for different temperatures and durations.

  • Many thanks for this however as I said in my initial post I am working with just two smart thermostats and an extension kit.

    Your setup sounds great but as I have 19 radiators it also becomes too expensive for me.

    So I am specifically looking to see what other folk have done with regards a three channel setup.

    Many thanks for your help
  • Hi Damo,

    Could I ask, are the Smart Thermostats in relay mode (wired) and not wireless? I'm guessing they are wired to a motorised valve which controls the heating zone.

    In my setup, I had 3 channel Programmer, hot water, ground floor CH1 and 1st floor CH2; each heating zone had a room stat; one in the hallway and one in the master bedroom.

    My first update was to replace my room stats with Smart Thermostats and the 3CH programmer with the Extension Kit. I had connected both heating zones to the same connection CH on the extension kit. Simple and straightforward. Need heat? Smart Thermostat would switch 'on' and the Extension Kit would switch on the CH providing power to the Smart Thermostat, in turn operating the motorised valve for that zone/ floor and then turning on the boiler. If the other Smart Thermostat did not request heat then that heating zone would remain off/ cold. If both did then all CH zones would get heat.

    However, I wanted more control. I've since upgraded all the radiators (9) with Smart TRVs. Tado Support setup Zones/ Floors, added Smart Thermostats and TRVs to their respective zone/ floor. Soon ran into a problem with the setup; asking for heat from a Smart TRVs on the 1st Floor would not turn on the boiler.

    I asked Tado support; Answer, due to backend configuration Smart Thermostat on the 1st Floor would not allow switching on the extension kit for CH. After explaining to Tado Support, they said it is possible and would require the support of an electrician to rewire. Tado would also update backend configuration.

    After a little research, I ask Tado Support to remove CH from the Extension kit and only use the Smart Thermostats to switch on the heating zones. Now, when a Smart TRV asks for heat it will ask Smart Thermostat assigned to that zone/floor to switch on the motorised valve, which operates the boiler. As I have Smart TRVs on all radiators the Smart Thermostats are set for a lower temperature; anything below 17oC, if they operate with no request for heat from a Smart TRV the boiler would switch on the would flow would run through the bypass valve. I did not need the support of an electrician; just needed to move two CH wires at the extension kit. Think relay; normally open/ normally closed.

    Hope this helps.

    Kind regards, Sparky

  • I am interested in the outcome of this as I have a similar system but with underfloor heating downstairs instead of radiators.

    I was wondering if I needed to have a second extension kit or just a standard thermostat to control the underfloor heating and valve for this section that would also be able to control the boiler when required?

  • Sparky, that explanation is a great help for me thank you. Could I trouble you with a couple of follow on questions please?

    I've a similar 2 CH zone+ HW system as you. I've installed 2 tado smart room thermostats in each of the zones. Final part is to replace the programmer with the extension kit to be able to control hot water. Tado have paused my online installation saying tado is incompatible with a 3 channel system. Like you I can see I should just wire both existingCH ON wires to the single CH ON terminal on the extension kit, and let the call for heat from the smart thermostats drive the zone valves and boiler. I've explained this to tado and asked for installation instructions based on an equivalent 2 channel system and wait for a response.

    So I can wire the extension kit, but could you explain what other configuration steps you took please?
    I understand you have to configure hot water control on one of the thermostats?You mention you asked Tado to reconfigure the extension kit to remove CH? How did you ask please? I'm wary of switching off the CH ON line from the extension kit to the 2 thermostats. As long is it stays always on, I know that's fine as the thermostat will do the switching.
    Finally, when you do this yourself does the HW appear in the App? Tado have paused my my installation and I'm conscious I might also need tado to do something to enable my extension kit, that they might be reluctant to if I've installed against their guidance.

    I feel so close to having the setup I wanted, and it's frustrating to see that tado will in fact support my 3 channel system, just that they don't realise it!

    Thanks in advance! :)
  • @ExcessiveJimbo I'm also interested in this outcome. Was this ever resolved. I have moved into a house that has 3 zone system and my existing extension kit and wireless stat aren't compatible. I have asked Tado and they have said it cant be done. But what @Sparky suggested makes perfect sense about wiring both stats to one circuit in the extension kit. What is meant by reconfiguring the extension kit. Can Tado actually remove iotems from individual extension kits?

  • Hi @Morbster and @ExcessiveJimbo, my wiring setup bypasses the central heating side of Extension Kit. Tado setup my Heating Zones and did some backend configuration changes but I think you can do these through the web app. Settings, Rooms and Devices, Heating Zone, changing Zone Controller. Below is the settings for the Master Bedroom:

    The Heating zone controller is set to the Zone Smart Thermostat, for me 1st Floor. So when the Smart TRV calls for heat it will activate the Zone controller this then switches the motorised valve for that heating zone which starts the pump and boiler.

    What I have discovered the Smart Thermostats do not need to be calling for heat and can be set to Off, 24/7.

    Thanks, Sparky

  • Marcilud
    edited April 2021


    Just to let you give some update.

    I Did have 3 zone controller from EHP  exactly EHP R37-HW   from original installation has been all   electric valves all wiring as per EPH specification

    Hot water, and 2 heating zones. I have  bought Tado V3+ wireless thermostat (probably better will be wired kit ) with hot water control item 104005 (refurbished:) ,additional to that bought smart thermostat (wired).

    Configuration is as follow wireless receiver is controlling hot water and zone 1.

    Smart thermostat is controlling zone 2 independently (valve 2). in the setting need choose Zone controller to None (work as independent).

    Hope that will help someone .

  • @Marcilud Hi, I am in the same position as you. I have a 2 zones setup ( 1 thermostat on the ground floor and 1 on the 1st floor, both are EPH CM2 ) with a EHP R37-HW programmer. The boiler model is Potterton 18s with a hot water tank. Would you be able to share the configurations as Tado was not able to support, mentioning that my system is a 3 relay system instead of 2 and it may be possible to use the Tado Wireless Starter Kit if rewiring. I would appreciate it if you could provide assistance in order to set it up. Thank you

  • Jurian
    Jurian | Admin

    Our recommendation:

    With a triple channel programmer, hot water control should just remain on that programmer. Just set the heating to "always on" for both heating zones.

    Afterwards, just replace the 2 wired thermostats with tado wired wall thermostats and you have full heating control with tado.

    If you absolutely need hot water control with tado, we fully recommend you hire a heating electrician. This person should then "permanently bridge" both heating zones in the existing programmer.

    The tado wireless receiver (part of the wireless starter kit, or you can buy it from webshop separately) should ONLY be in control of the hot water zone. Both heating zones should only be controlled by the 2 wired tado smart thermostats.

  • @Jurian I have a similar issue with replacing a 3 channel programmer (Horstmann ChannelPlus H37XL Series 2).

    I have installed a wired Tado thermostat to replace an existing CH zone room thermostat but need to get the Tado V3+ wireless thermostat installed to replace the other wired thermostat (currently above an oven) for the other CH zone and ideally the hot water as well.

    The wired thermostat is working fine with the zone in the original programmer set to always on.

    I had checked with support before purchasing that it would be possible to use the wired and wireless combination to meet my needs so I'm hoping you can advise on the steps required because I cannot get installation instructions via the app.

  • Hi all,

    I have a 3 CH setup similar to most of them in the thread. Downstairs and Upstairs heating zone and HW with respective 2 port valves (S Plan or S Plus plan) . I had a Honeywell St6400C with Honeywell 230v manual dial thermostats.

    Currently I have got the Tado Ext kit and 2 wired thermostat. 1 in upstairs and 1 downstairs.

    Had a new boiler replaced so the electrician came to wire the boiler helped me to install the Tado system (He never did Tado before). So we read the instruction and wired.

    Attached is my current wiring. I am not good at Electric terms, here it's mentioned that we need to "permanently bridge" both heating zones in the existing programmer.

    I am getting the electrician back but he seems to be not happy with Tado and he was keep on mentioning that I should have gone with Hive. So he mentioned that I need to tell him what to bridge as he is not familiar with Tado.

    Would you explain in a easy way to understand this.