tadoWireless Temperature Sensor X – Add-on Product for Smart Radiator Thermostats X, for Optimum Heater Control, Save Energy and Costs, Easy DIY Installation, Not Compatible with tado V3+

We have a Glow-worm Ultracom 38 cxi combi boiler with a Drayton electro-mechanical 2 wire wall thermostat that we wanted to replace with the tado smart thermostat.The thermostat was getting end of life and would often need the contacts cleaned before switching the normally open (NO) 24 VDC heating control from the boiler. The other issue was the lack of intelligent heating control whereby the house was either cool or hot with frequent intervention needed to increase and decrease the thermostat set point.Most new thermostats on the market, smart or otherwise, could improve the control situation but after installing Alexa we wanted to add heating to the list of house devices that we now control. We also thought that having the ability to monitor and control the home environment over the Internet might be useful.Research began on two commonly known products and they both looked fantastic. The problem with the UK models is that there didn’t seem to be a 'wired' switching thermostat model (where the thermostat itself did the switching) available and a wireless receiver had to be installed at the boiler. I thought it pointless to install a wireless receiver and start altering boiler wiring when we already had wires installed to the existing thermostat. Hot water did not need controlling.It was a relief to discover that tado could replace an existing wired thermostat and in our case switch the 24 VDC circuit using the common-NO wiring configuration.The Tado was ordered and arrived quickly. Although being an electrician by trade I followed the Tado instructions that started at the Tado setup web page; I didn’t want to be the one causing a boiler meltdown in the middle of winter by getting things wrong.The start of the install involved creating an account then registering the smart thermostat and the Internet Bridge that plugged into the Ethernet port of the router. Recognition and configuration of tado components was slick without problem. The installation then asks your thermostat and boiler make/model/setup. It was good to see that the Drayton and Glow-worm Ultracom 38 cxi was included in the list. The Ultracom 38 cxi is listed as Ultracom --- cxi as it includes all three (24, 30 and 38) cxi models.The boiler unit was powered off and the instructions gave the wiring diagram which was as expected in my case having metered out the wires beforehand. The wires were labelled using the stickers provided.Mounting of the new thermostat was easy in my case as the existing screw holes from the Drayton matched the tado smart thermostat. The unit could be mounted without any more holes being put in the wall although I did have to chase the cable hole a little. I am not sure if the tado would benefit from a built in level like some of the other models have although this was not an issue as we have a few levels about the house and can resort to the mobile app level if needed.Tado thermostat common and NO were used for the boiler heating switching control with the earth wire being terminated into a spare isolation terminal. After replacing the wiring cover then clipping on the smart thermostat, we were ready to power on the boiler.After manually altering the heating using the manual controls on the smart thermostat and checking the boiler operated in a similar way as the old thermostat, it was time to install the app. We have both android and apple devices in the household and the app installed and worked well on both.We switched off the heating schedule function built into the boiler. There were instructions with the tado but we left the old boiler schedule as is and switched off the boiler 'Central Heating Timed Mode'. This was done by pushing the mode button on the boiler until only the 'Central Heating Function' and 'Domestic Hot Water Function' icons were displayed in the boiler LCD display.The tado app heating schedule gave us what we could not get from the boiler timed mode and that is work week/weekend programming. An individual day programme was also available. We now have frost protection which we never had if the boiler schedule or control had the boiler heating off.The app works well over the Internet when away from home and we have had no issue with performance. For some of the colder days it was good to switch on the heating a bit early before leaving work as the inside temperature had dropped with the heating off. We could change the off time to a minimum threshold to alleviate this maybe in the future.The saving in the heating bill will come from the fact that we seldom overshoot with excessive heating of the house. Having intelligence built into the control, the smart thermostat will alter the heating as the room temperature reaches the set point. The analytics that come with the app show when the boiler was switched on and off over time so you can see your burn rate versus temperature and humidity.One tip if using the schedule is to change the 'Settings' -> 'Heating' 'Manual Control on tado device' from 'Until ended by user' to 'Until next automatic change' otherwise a change in temperature by the user will override the schedule 'next time' until you cancel manually.Alexa was easy to setup and with Alex Show and the Alex Dot in another room inherited the setup. A voice command to check the inside temperature brings up a digital thermostat on the Alex Show screen where the temperature can be altered using the touchscreen interface. Setting heating up/down or to a specific temperature is easy with voice control.We get all of the functionality mentioned and more without spending a penny on subscriptions. We don’t want the features the subscription entitles us to so this is not an issue.The tado smart thermostat gets five stars as it has surpassed my expectations from installation to operation. It also provided the wired thermostat replacement with the flexibility to add a boiler extension kit if the heating control is more complex and/or the water heating is to be controlled. If we want to build on the system to make it multi-room with additional smart thermostats and/or smart radiator thermostats then these options are available.

The Tado thermostat is a really good way to control your central heating, there are several useful features and all can be controlled using your smart phone, for example you can set the system to reduce the temperature when your away from home and bring it back to normal just before you arrive home, all done automatically by using the GPS on your phone. From the app one can also check your daily usage and cost.The system is fully programmable to suit your lifestyle. I think this is a great product, it’s easy to install and I highly recommend it.

I purchased the smart thermostat in November 2020 to replace my old mechanical thermostat. I was already aware that the automatic shutoff while away was a subscription feature so I won't take any stars off for that. Having said that, even without paying for the smart features, the app will ping you a notification when you leave the house asking if you want to set "Away mode". Yes it's not as convenient as having it set automatically but it is still really helpful and easy to set Away mode of you're out for a few days.The main purpose of this review is just to report on the very high quality of the thermostat, the installation instructions and the app. You can really tell they spent time paying attention to the smallest details which really sets it apart from the typical Chinese IoT hardware out there. I am a software developer and hardware tinkerer so I recognise the effort that went into the Tado thermostat.I was also a bit concerned about battery life as my thermostat has no power cable. Well it took 7 months before I could write this review because that is how long the 3 AAA Duracell batteries lasted (217 days actually). 5 weeks ago I received an email telling me the batteries were low but not to worry as they would still last another 3 weeks. I also got a warning when viewing the app. (this is the kind of thing I mean when I talk about attention to detail).As for the actual benefits well for me what I like is:- keeps the correct time (unlike the mechanical timer on my boiler)- shows me a graph of the room temperature over time so I can see how well the heating is performing- shows humidity over time which is useful in winter as I get dry hands or in summer as it might feel hotter than the thermostat would say otherwise.- lets me control the temperature from my phone so I don't have to get up from where I'm sitting- lets me control the settings from outside my house so I can make sure it is off when I'm away or warming the flat before I arrive- lets me control the temperature via my phone's assistant (I don't have Alexa or Google home but it still works directly through my phone)- setting a heating schedule is really easy and intuitive via the app- battery lasts over 6 months!- never has trouble connecting to my WiFi despite the fact that I turn off my router every night. Well the thermostat is very close to the router so I can't test the range but some of my other devices only connect 9/10 times. The Tado connects quickly 100% of the time.