Swapping Salus RT510RF to Tado system


Hoping someone can help. I used to have Tado fitted at home until I replaced this with Heatmiser controls due to introducing underfloor heating. The Tado equipment I have is the Internet bridge to connect to the router, a Tado Extension kit and 2 x wired Smart Thermostats.

My son has recently moved into his new home. The heating system at his house comprises of a Main ECO COMPACT 30kW Combi Gas Boiler, a Salus RXRT510 receiver which is wired to the boiler and a Salus RT510TX wireless thermostat. I would like to replace the Salus setup in my son's home with the Tado system so that my son can control his heating remotely via the Tado app.

Is this possible? I have attached photos of the Extension kit and the two Smart Thermostats.


  • policywonk

    Sorry, am not a professional, however have had previous experience of using both Salus controls and Tado in my home.

    As I understand it, your boiler is defined by the wiring specs given in page 31 of this document: M15263_CL_Gas_Boiler_2.eps (mainheating.co.uk). If I've read that document correctly - and hoping it is the correct installation guide - it should not need external HW controls because it seems to be an on demand boiler for HW, timer and thermostats only apply to the CH circuits. So all you should need to commission is the room thermostats.

    Assuming you are comfortable with handling wiring, it seems that the Live, Neutral and Earth connections are already identified on the chocolate block connector at the boiler. The connectors marked as [1] provide a live feed to the thermostats, and the connectors marked [2] take the switched live feed from the thermostats.

    So, in short, the installation steps are:

    1. Install the Tado app on the mobile phone required.
    2. Run the wiring like this:

    * From screw point [1] on the boiler, run LIVE to each thermostat's COM connector point.

    * From screw point [2] on the boiler, run SWITCHED LIVE cable to the NO connector point on the thermostat.

    I presume you'll use twin core plus earth cable, with LIVE being BROWN and SWITCHED LIVE being blue. If you have spare black insulating tape, it will help wrap that around the visible part of the blue cable feeding the thermostats. That will signal to most electricians that it is meant to be a Switched Live feed.

    1. Mount the backing plates on the relevant walls.
    2. Using the Tado app first install the bridge,

    a. Grab each thermostat cover (thats where the brains are present) make sure they both have good batteries,

    b. Decide which one belongs to the specific rooms you want

    c. Use the mobile phone on which the app is installed, to scan the QR code on the each thermostats, one by one, assigning the specific rooms as you go - and make sure they are recognised in the App.

    d. Place the covers on the wall. Force one to turn on the boiler manually by manually raising the temperature to 25 cent, to test it's circuit, then the other. Then reset to normal temp once proven.

    e. Then set the temperature by time of day for each room. DONE.

    The boiler should just produce hot water by itself without the need for the extension kit to be installed - unless you've added a hot water tank. In which case, the wiring is a little more complex, but not a lot.

  • Tonygrewal1

    many thanks @policywonk for your detailed response. I will have to check my son's boiler when I am there next but if I am not mistaken, the front of the combi boiler looks more like this (https://www.mainheating.co.uk/main-products/gas-boilers/combi-boilers/main-eco-compact-combi) than from the boiler you have shared.

    I should have mentioned before but the boiler and Salus RXRT510 receiver at my son's home are currently in the bedroom on the first floor. The boiler is located inside a cupboard in the bedroom and the Salus receiver is just outside the cupboard. The wireless Salus thermostat is positioned in the living room on the ground floor.

    From the information you have sent, it would be impossible to run a cable from the boiler (first floor bedroom) to the Tado thermostat (ground floor living room). There is no hot water tank since it is a combi boiler.

    Before I posted on the Tado community, I posted on the DIYNOT forum (https://www.diynot.com/diy/threads/salus-rt510rf-to-tado-system.626690/#post-5695219). From the responses I received from my post, it appears I would still need to connect the Tado Extension kit (in place of the Salus Receiver). Do you see any issues from the responses I have received on that post? My next step is to take a photo of the wiring on the Salus Receiver and upload it on my post on the DIYNOT forum.

  • policywonk
    OK Got it!
    Page 44 and 45 of that boiler's manual gives the wiring.
    The G block takes in the mains supply to the boiler on pins 4 and 5. The same block on pins 1 and 2 provide the cabling points for the thermostat.
    1. Wire in the extension box so that it piggy backs its supply, live from live, neutral from neutral from pins 4 and 5 on the boiler's G block. This gives the extension box power.
    2. Wire pin 2 from the G block to COM on the heating pins of the extension box. Wire pin 1 to the NO heating pin.
    3. Scan the QR code along with the Internet bridge code and the extension kit should now be in a position to control the boiler. Test that it does work.
    4. Now fit the thermostats where you want, scanning the QR code to tell the app where they are placed. Once they are logged into the app they should be able to tell the extension kit to turn on the boiler when necessary.

    This is literally a one hour job. I was confused because you had purchased wired TADO thermostats, so I assumed you wanted to hard wire them. They can also be used as fully wireless thermostats.
  • policywonk
    policywonk ✭✭
    edited March 18
    Oh forgot. Three things.

    1. Take photos of the Salus wiring before you remove them. This way if something goes wrong your can put back the original wiring.
    2. According to the manual pins 2 and 1 are Live and Switched Live respectively. So you need to set the extension box setting to 2.
    3. As this is all Live don't forget to isolate the boiler before you start work
  • Tonygrewal1

    thanks @policywonk. I will look to take a photo of the Salus wiring and upload on this post before doing anything else. Whatever is wired to the Salus Receiver, would I not be able to wire these to the Tado Extension kit rather than having to go to the Boiler terminal blocks?

    As I already have a Tado account and have the Tado devices (Internet Bridge, Extension Kit, 2 x Smart Thermostats) registered to me, would I be better off unregistering them first so that my son can create a new Tado account and register these devices to his home? I am not sure what the best & easiest way would be

  • policywonk
    Hi. I would trace back the wires to find out where they were sourced. This way you will have access to the logic in your head so if something goes wrong you have a shot at working it out. If that worries you take the photo anyway.

    The app has a capacity to allow you to invite others to control the house. But yes. Reinstall then from your app. Reinstall then via your sons phone. Almost there...
  • Tonygrewal1

    morning @policywonk. I’ve attached a photo of the wiring to the Salus Receiver. I was not able to remove the cover of the boiler to see the wiring on the boiler terminal block as I didn’t have the right screwdriver.

    Does this photo help to see how best to wire the Tado extension kit? From the way the Salus Receiver is wired, it looks different to the way you described it earlier but I may be wrong. There is a link wire between L and COM. Also, I noticed the earth wire coming from the boiler (or pump) has a brown sleeve on it just as it's wired into 'NO' on the Salus Receiver.

    Reading one of the responses from my post of the post from the DIYNOT forum (https://www.diynot.com/diy/threads/salus-rt510rf-to-tado-system.626690/#post-5695219), someone said "If there is a link wire in the RXRT510, between L and COM; the L can be placed into the Tado's COM terminal and the link wire can be disposed of". They also said to swap the jumper on the back from position 2 to position 1.

    I have attached a photo of the 'jumper' position at the back of the extension kit. When I pulled it out, it appears it was in position 2. 

    Looking at my Tado extension kit, I noticed it has two wiring sections - 'Relay wiring 1 - Potential Free' and 'Relay wiring 2 - Switched Live'. Which one of these wiring sections would be used?

    Going back to the Tado app, do I need to unregister all the Tado devices first from my account, and then get my son to install the Tado app on his phone (and create a Tado account) before rgistering these Tado devices under his Tado account?

  • policywonk
    Hi. There is one question which needs to be settled- whether the wiring to the Salus box is true Live, or not. The COM terminal seems to be live, the NO is switched Live, the blue wire may be genuine Neutral. You'll need a mains tester to confirm. If at least the COM pin is Live, then the Tado settings are set to 2, not 1. COM goes to COM, NO to NO.

    YES best to deregister from your account first and re register on your lad's phone.
  • Tonygrewal1

    thanks @policywonk - I was able to connect the Tado yesterday and it's all up and running 😊

    The Tado instructions are really good as well as the Tado support team. The Tado jumper setting was 2

  • policywonk

    Well done, good luck.