Tado Smart Radiator Thermostat – what you need to know
| Price when reviewed | £55 (stand alone) |
| Subscription price | Auto Assist (optional): £3/month or £25/year |
| Score | ✭✭✭✭✫ |
| Ease of install | ✭✭✭✭✫ |
| Award | Recommended |
The Tado Smart Radiator Thermostat is a smart thermostat designed to control a single radiator. It’s available in two versions, for vertical or horizontal mounting, where the only difference is the orientation of the display. The radiator you’re planning on fitting it to needs to already have a compatible thermostatic radiator valve (TRV).
| Smart Radiator Thermostat (vertical) | Smart Radiator Thermostat (horizontal) |
You can buy the Tado Smart Radiator Thermostat as a stand-alone item, but it’s also available as a starter kit, which includes the internet bridge you’ll need if you don’t already have any Tado devices. You can buy the starter kit with either the horizontal or the vertical type.
| Smart Radiator Thermostat Starter Kit (vertical) | Smart Radiator Thermostat Starter Kit (horizontal) |
| Pros | Cons | ||
|---|---|---|---|
 | Comprehensive system |  | Limited control without internet |
| Discreet design | | Subscription needed for the smartest features |
| Easy installation | | Fussy about batteries |
| Works with multiple smart assistants and IfTTT | | Best used with a Tado Smart Thermostat |
What is the Tado Smart Radiator Thermostat?
Tado’s Smart Radiator Thermostat is a cylindrical smart controller that replaces the head on a thermostatic radiator valve. Powered by batteries, it contains a powerful motor to open and close the valve, adjusting the amount of water flowing through the radiator.
The Smart Radiator Thermostat receives its instructions from the Tado system. If you don’t already have any other Tado devices you’ll need to buy the Smart Radiator Thermostat as part of a Tado Setup Kit, which includes the necessary internet bridge.
Tado Smart Radiator Thermostats can’t switch your central heating on and off by themselves, so they’re of limited use if your central heating is controlled by a conventional thermostat or programmer. In this situation you’ll be able to use them to control the heat in a single room, but they can only regulate the heat when the boiler is already running.
If you already control your heating with a Tado Smart Thermostat, the Smart Radiator Thermostats make much more sense. In this scenario, individual room thermostats can call for heat whenever they need it, turning the boiler on if it’s not already running. This allows for wonderfully fine control – for example, preventing a baby’s room falling below 18℃ overnight.
Tado Smart Radiator Thermostats are ideal for homes with an always-on community heating system – a rarity in the UK. Whether you have this, or a Tado-controlled boiler, ideally you’ll need Smart Radiator Thermostats on every radiator to prevent unwanted heating in other rooms.
Installing the Tado Smart Radiator Thermostat
Tado’s Smart Radiator Thermostat can be very simple to install. Provided your radiator already has a compatible TRV, you just unscrew the existing head and replace it with the smart controller. You can use this link to check if your radiator valve is compatible with Tado (PDF).
Older radiators may have straightforward manual valves, rather than TRVs. These aren’t compatible, and you’ll need to replace them before you can fit the Smart Radiator Thermostat. While this can be an expensive job, it will make your heating more efficient – even in rooms where you don’t plan to fit a smart controller.
Once the Smart Radiator Thermostat is installed it will calibrate itself, after which you can enter the Tado app and add it from the Rooms & Devices section of the Settings page. If you don’t already have any Tado devices, you’ll first need to plug in the internet bridge to a spare port on your router, and connect it to a USB port or the supplied power adaptor for power.
Configuring the Tado Smart Radiator Thermostat
Once the Smart Radiator Thermostat is fitted, you can set the temperature you want in the room by simply turning the ring on top of the controller. You can also use the Tado app to manually set a temperature, or to create a Smart Schedule. It’s important to realise that on its own, the Smart Radiator Thermostat won’t be able to heat the room unless the heating is already switched on.
If your heating is controlled by a Tado Smart Thermostat, the Smart Radiator Thermostat will communicate with it to fire up the boiler when needed. That’s a great scenario if you’ve got plenty of Smart Radiator Thermostats providing individual control to every room, but if you’ve only got the one you should use caution – when it calls for heat, all the other radiators will get hot too.
Using the Tado Smart Radiator Thermostat
It’s easy to forget the Tado Smart Radiator Thermostat once it’s configured how you want. In use you’ll hear a smooth, muted whirr as the motor operates the valve. At times this can appear a bit twitchy, briefly whirring every now and then even when the heating isn’t running, but you soon get used to it.
Smart radiator thermostats are fitted close to the radiator, so they can be influenced by the heat of the radiator itself. We generally found this wasn’t a problem with the Tado Smart Radiator Thermostat. If you have other Tado Smart Thermostats in the room, you can choose which one controls the heat. This could lead to more accurate temperatures, particularly if the other thermostat is sited away from the radiator.
We did notice that the Tado Smart Radiator Thermostat allowed the room to overheat by half a degree or more. Our best guess is that the system doesn’t fully account for the residual heat in the radiator once the valve has been closed. Like other systems, Tado’s open window detection is based on sudden changes in the measured heat or humidity. While it’s usually reliable, you can accidentally trigger it by walking in from a cold hallway, or hanging damp washing up nearby.
Tado’s app gives you a good visual indicator of the room’s temperature and humidity, warning if you need to open a window to freshen things up. There’s also a historical view that helps you understand how sunshine or your daily routine affects the room’s air quality.
What’s the wireless coverage like?
The Tado system uses 6LoWPAN, a purpose-designed wireless standard for low-power Internet of Things devices. Tado uses the 868MHz frequency band, which should give its system greater range than standard 2.4GHz or 5GHz wireless networks. It should also make it less susceptible to interference, for example from your microwave oven or Wi-Fi. We have heard some reports of connection problems, but we experienced no issues over the three floors of our test home.
Does it work with rechargeable batteries?
Tado recommends you use only alkaline batteries with the Smart Radiator Thermostat, and these do need replacing regularly – we’ve found that even good quality ones can be flat within a year. Rechargeable batteries do work, but the app reports that the device has low battery even when they’re freshly charged. Because you subsequently can’t rely on the low battery warnings, it’s best to charge the batteries a couple of times per year to avoid being caught out when they actually do go flat.
Will it work without an internet connection?
Most of the Tado Smart Radiator Thermostat’s smart behaviour is controlled by Tado’s servers, so losing the internet presents problems. Scheduled behaviour and other adaptations all stop, and the radiator is left doing what it was last instructed to do. You won’t be able to control the thermostat from the app, but you can at least control it manually by turning the ring. You won’t be left without heat, or with heat that you can’t switch off.
A power cut will, of course, stop your heating working altogether. Once the power returns, the Tado system is likely to recover before your boiler has completed its power-on self checks.
Should I buy the Tado Smart Radiator Thermostat?
We wouldn’t recommend the Tado Smart Radiator Thermostat unless you also have a Tado Smart Thermostat controlling your central heating. If the Tado system isn’t also controlling your boiler, the radiator thermostat will always be at the mercy of whether the heating’s actually running.
However, as an upgrade to an existing Tado system the Smart Radiator Thermostat can be very worthwhile. Controlling individual radiators lets you set the heat accurately and separately in every room. This is brilliant for larger houses where some areas go unused, or, for example, when the kids go to bed earlier than you and you don’t want to heat all the bedrooms.
The Tado Smart Radiator Thermostat is a great addition to a Tado system if you want this level of control. However, for the best results you’ll need to buy one for every radiator, which will soon get expensive.
Specifications
| Manufacturer | Tado |
| Product name | Smart Thermostat |
| Size (HxDxW)mm | 104x104x18mm |
| Weight | 137g |
| Connection type | Proprietary bridge (6LoWPAN) |
| Works with | Alexa, Google Assistant, Apple Homekit, IfTTT |
| Sensors | Temperature, humidity |
| Display | Mono LED |
| Batteries | 3xAAA (rechargeable OK) |
| Other requirements | Tado internet bridge (included with Tado starter kits) |
| System limitations | Maximum 25 devices, 100 users |
| Warranty | Two years |
| Date tested | November 2020 |
