Troubleshooting the tado°

Yesterday I installed a tado° smart thermostat in our apartment. The tado replaced a Honeywell CM901 thermostat and is connected to a Viessman Vitodens 100-W WB1A boiler. This post gives an overview of the installation process and my notes on troubleshooting the tado.

The tado (December 2013) is actually three devices:

  • tado gateway/bridge – Connects to an internet router via an ethernet cable.  Communicates wirelessly (6LoWPAN, 868 MHz) with the tado box. Needs USB power.
  • tado box – Connects to the boiler and controls when the boiler starts or stops heating. Powered by USB power (or by the boiler in some cases).
  • tado temperature sensor – Measures the temperature and communicates wirelessly (6LoWPAN, 868 MHz) with the tado box. Has an internal battery that is normally charged via solar cells on the device. Can also be charged via USB power.

A USB power adapter and a very short ethernet cable are included. It should be pointed out that if you can’t get USB power from your router and you also can’t get power from your boiler, then you will need a second USB power adapter.


The installation process was fairly straight forward, though not trivial. If you want you can pay tado° to have one of their engineers do the installation. The tado doesn’t come with a printed installation manual. Instead you log on to the tado° web site and follow an installation wizard. I suggest doing this on a tablet or laptop since you will probably want to have the instructions at hand by the boiler during the installation.

Following the steps in the wizard was okay. Although there is this video on YouTube, what I missed was an overview of the entire installation process. Also, once the tado is installed and working, there doesn’t seem to be a way to access the wizard again in case you want to look something up.

The installation starts with connecting the tado gateway to the internet. This was trivial. The wizard immediately detected that the tado gateway was online.

Next was installing the tado box by connecting it to the boiler. This was by far the most nerve-racking part of the installation. In summary, you have to open your boiler, disconnect the old thermostat and connect the tado box instead. I recommend carefully studying the schematics of your old thermostat and comparing them to those of the tado box. It worked out in the end. The gateway and box found each other and the “link” LED on the gateway lit up. The wizard detected that the box was connected.

The last step was installing the tado temperature sensor. I removed the protective foil from the solar cells as instructed, but the wizard did not detect the temperature sensor. I tried reseting the sensor with a paper clip, but that did not help either. I then connected the temperature sensor to USB power to charge it (tado° recommends 24 hours). I continued trying to get it to work while it was charging. I reset it a couple of times and eventually the temperature sensor’s LED started blinking. Still no connection though according to the wizard. Maybe the temperature sensor did not have enough charge yet? After several reset attempts and some waiting the wizard detected that the temperature sensor was online. I could complete the wizard and finish the configuration. Everything was working.

My tado soon started having problems though. The tado web site and the mobile app would either not show a temperature reading or would complain that the tado box had no internet connection.

Dropped connections

Dropped connections

In our apartment the internet router (with wifi) is in a cabinet together with a cable modem and the fuse cabinet. After lots of testing I eventually replaced the provided ethernet cable for the tado gateway with a longer one and moved the tado gateway as far away as possible from the other equipment in the cabinet. Since then I haven’t had any problems. I think interference from the other equipment was causing the connection gateway-to-box to drop. I think the reason the connection box-to-temperature sensor was dropping was because the temperature sensor’s battery initially didn’t have enough charge.


First, I should point out that the tado° support team was quick to answer my questions on Twitter. I should have tried contacting them earlier to save myself some grief, but I simply assumed there wouldn’t be any customer support over the weekend. It’s nice to be pleasantly surprised!

When the tado has connection problems the Android app and web app show instructions on how to solve the problem. There is also a FAQ in the web app under the Support menu item with some useful tips. Sometimes though, I found that the instructions didn’t always fix the problem. Below are my notes on the different failure modes of the tado that I noticed and what actions seemed to help.

Disclaimer: My notes may not be correct. Use them at your own risk.

  1. Blinking LED on tado box and blinking “link” LED on tado gateway and error message in app about no connection to the internet
    1. Reset tado box using paper clip.
    2. Optionally (?) reset tado gateway using paper clip.
  2. Blinking “link” LED on tado gateway and error message in app about no connection to the internet
    1. Unplug power from tado box.
    2. Thermostat switch in tado box clicks (not always?).
    3. Plug power in again.
    4. “link” LED on tado gateway stops blinking.
    5. Web app shows yellow status for inside temperature but no temperature is displayed. I assume this means the tado gateway has a connection with the tado box, but the tado box has not received a temperature reading from the tado temperature sensor yet.
      Inside temperature not detected
    6. LED on tado box continues blinking. (What does the blinking LED mean?)
    7. Reset tado temperature sensor using paper clip.
    8. LED on tado box switches off.
    9. Web app shows inside temperature.
    10. I think it would be more convenient if the LED is on when a connection with the temperature sensor is established.
  3. tado temperature sensor has no connection
    1. Reset the temperature sensor using paper clip.
    2. The temperature sensor LED blinks 28 times. (Why 28 times?)
    3. The temperature sensor LED switches off.
    4. Web app shows inside temperature.
    5. I think it would be more convenient if the LED is on when a connection with the box is established. Or would the LED use too much power if constantly on?


Once my supposed interference problems were solved earlier today, the tado has been working perfectly. It will be very interesting to see how well the geofencing works tomorrow when we leave the apartment for work.

tado° dashboard

tado° dashboard

Update: tado° support has provided me with info about the LEDs:

  • tado box LED
    • orange – home button was pressed
    • green blinking – no connection with the tado gateway
    • off – everything is working
  • tado temperature sensor LED
    • green blinking – no connection to the box
    • off – everything is working

I think the problem with using the LED in off state to indicate that everything is working is that it could also mean that the device has no power (or be defective).

  1. My Tado was installed by an electrician but not convinced my temperature sensor is working and two thermometers say 21 and it thinks the house is 24.5 and there are no lights on temperature sensor. The supplied Micro USB lead was defective so didn’t really help that it probably hasn’t been charged.

    Verdict on hold….

    • Claes said:

      Is the webapp showing an indoor temperature reading? If that’s the case I think the temperature sensor is at least sending values to tado. I guess the temperature sensor could still be defective though and be sending incorrect values. Maybe the temperature sensor is just off by 3.5 degrees compared to your other thermometers?

  2. There must be a sensor in the Tado box as no lights on the temp sensor, even after charging and resetting and I stuck it in the fridge for a few mins and the temp still rose due to the Tado being next to the boiler. Looks like a faulty sensor, hopefully the can send a new one.

    • Claes said:

      When I reset my temp sensor it’s LED blinks a 28 times and then the LED goes out. In other words, when the temp sensor is working properly the LED is off.

      When you say the temperature rose, do you mean that the value displayed in the webapp rose while the temp sensor was in the fridge?

      • There is an LED on mine but it doesn’t work, no sign of life even after a reset. The temperature rose while it was in the fridge. The Micro USB lead they gave me is very poorly made and didn’t fit into either the sensor or the Tado easily so it may well have damaged the sensor connector while I was trying to insert it. Worse than that, it doesn’t provide power either. Two of my own micro USB cables are fine in the Tado but not theirs.

        The temperature continued to show a rise while the sensor was in the fridge and Tado said they’d disabled it in the setup email but I doubt that would include permanent off i.e. a reset would still power it on, I’m guessing they just tell trey Tado box to ignore it.

        The heating seems to have settled in a bit, we were about 60 miles away today and it was off, not at full temp when we got home but warm enough.

      • Aha, all working now. Tado remotely enabled the sensor and whenI went into the app, it told me it could’t detect it and suggested I reset it by using the top hole, not the one with the circle round it like I’d been trying all weekend…. That’s the reset on the other two devices. My wife did it as I was at work and the shown temperature immediately dropped and Tado confirmed they can see the signal from it via diagnostics. The house is now at the ideal temperature as before t eh max I could get was 21.5.

        Thanks very much for your help with this.

      • Claes said:

        Good to hear that it’s working for you now. I haven’t had any problems with my tado once the initial setup problems were solved. My girlfriend and I are very happy with it.

  3. oops, just realised I repeated a bit about he fridge, emailing and bathing kids at the same time is not the best way to concentrate on one task!

  4. Mark Gracey said:

    Thanks for running through this. I had some similar issues. I ran through some of your steps but for me, resetting various devices in various orders didn’t seem to do much and then I found the ‘Factory Reset’. That seems to be a reliable way of connecting the system all back up together (at the very bottom of the Settings section). I’ve just done that and magically it all seems to have come alive again. The system, when connected seems excellent. I will see how it goes from here.

  5. JDR said:

    Very difficult installation on my side as my boiler was not in the list despite quick reaction of tado . They left me with mandatory call to the hotline in the UK. No document available anywhere, good idea to whave this installation workflow but high risk to leave the client without his gadget…. Especially when winter is coming.

    So I decided to do it alone, quite easy for tado Bridge, toujgh for the box connectee to the boiler (although standard, I got help from Nest installation guide and Honeywell as well, funny. The connection is rather easy if your boiler has a TA input on the board (2 cables connected on pins 1 and 4 + 230V on N/p pins)

    Eventually the bridge loks blocked in another connection (saying full light on the Link LED) so preventing my box and my therm. to connect. Impossible to know what the leds want to say. So after 1 week still not working, I’m very disappointed.

    In summary some docs must be given at least on the website + lack of information from the devices status (this should be available in the website)

    • Claes said:

      Sorry to hear that it is no success for you. I don’t quite understand what the problem is with your bridge.

  6. my sensor has now died and is being returned to Tado for replacement – it needs to be cloned. In the meantime, the heating is switching on around 4am. Tado tweaked my settings and it now switched the heating on at 5am, despite my rise time being set for 7:15. I’ve now moved my rise time to 9am and it seems to be getting the startup right.

    I saved no money in the 6 months I had Tado, still paying the same for gas as I did before and recently, since the sensor failed, it has been heating the house up too often and too hot, way above the temperature setting. It is using the built in sensor which I think is too close to the boiler and the pipes carrying the water around the house.

    • Claes said:

      How did you detect that your sensor was failing? My Tado is working fine as far as I can tell. I’ve had mine for almost a year and my gas bill is down from €44,60 to €35,43 = €9,17 saving per month. I’m renting the Tado at €8.25 per month. The price next year will be €6,99 per month. So for me it’s break even. Granted, last winter was very mild so I’m not sure if it was all the thanks to the Tado. We’ll see what happens next year.

      I have a temperature sensor that logs data to the cloud every minute or so. In the “temperature” chart you can see how my Tado is regulating on the heating: I have my Tado set to Savings mode, sleep between 23:30 and 07:00, home temp 21.5°C, sleep temp 16°C.

      For the Tado to be an improvement over a regular thermostat with a programmable schedule, you probably have to have an unpredictable schedule so that you get the benefits from the mobile app’s geotracking.

      • The iPhone app and my account both told me that the sensor wasn’t working. I tried resetting it, charging it and never got any lights to come on. In the end, Tado suggested I return it to be cloned.

        We have an unpredictable schedule, my wife works some days and not others so the geotracking works well for us, We had to set it to come on when we were home as our local school is quite close and when my wife was helping out there, the heating stayed on.

        we bought the device outright and I hoped to get a rebate from my power company as I felt I was paying too much each month but the bill matched the payments in the end.

        Ours also uploads to the cloud and I have it set to 22.7 and 16 overnight though it rarely falls that low – this isn’t the real temperature but what felt comfortable to us after raising and lowering it gradually over a week or two, The sensor in the boiler control seems to read about .9 above the remote sensor and I think the remote is at least .5 degrees out according to two other thermometers.

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