Best smart thermostat 2026: starter kit or extension?

The best smart thermostat in this comparison is the tado Wired Smart Thermostat X Starter Kit (2nd generation): it replaces your existing wired room thermostat, after which you control your heating with the app, for around €173. If there is no wire to the boiler or you want the thermostat somewhere else, the tado Wireless Smart Thermostat X Starter Kit (around €192) is the better choice. If you want to control radiators room by room straight away, look at the tado Wired Smart Thermostat X Multi Room Starter Kit at around €307.

Now that the heating season has started again, you only want the heating on when it's needed. A smart thermostat helps: you set a schedule, adjust the temperature from your phone and turn the heating down if you forgot to before leaving the house. In this buying guide we compare five products from the tado X range that are sold by several shops. We focus on the difference between a starter kit and an extension, and between wired and wireless, because that is where buyers most often go wrong. Dutch shops list these products under their Dutch names (Bedraad = wired, Draadloos = wireless, Startpakket = starter kit, Uitbreiding = extension), so the headings below use those names.

The best smart thermostats of 2026 at a glance

• Best overall: tado Wired Smart Thermostat X Starter Kit: replaces your wired thermostat, includes Bridge X, around €173
• Best wireless: tado Wireless Smart Thermostat X Starter Kit: freely placed sensor with a receiver at the boiler, around €192
• Best for room-by-room control: tado Wired Smart Thermostat X Multi Room Starter Kit: wired thermostat plus two smart radiator thermostats, around €307
• Best extension for a second zone: tado Wired Smart Thermostat X Extension: only works with an existing tado X system, around €114
• Best standalone sensor: tado Wireless Temperature Sensor X: measures the temperature in the middle of the room for your radiator thermostats, around €96

Starter kit or extension: what do you need?

This is the key question with tado: products with almost the same name differ a lot in price and in what they can do on their own.

A starter kit contains everything you need to get started. According to tado, the wired X starter kit contains the Wired Smart Thermostat X plus the Bridge X, which connects your tado devices to each other and to the app. The wireless starter kit contains a Wireless Receiver X, which you connect at the boiler, and a Wireless Temperature Sensor X, which acts as the thermostat in the room. That receiver takes on the role of the bridge itself, so no separate Bridge X is needed. If you are starting from scratch, always buy a starter kit first.

An extension is just the device itself, without a bridge. It doesn't work on its own, only as an addition to an existing tado system from the same product line: an X extension belongs with an X system. You use an extension, for example, for a second heating zone with its own wired connection, such as a separate underfloor heating zone.

So always check whether 'starter kit' or 'extension' is in the product name.

Wired or wireless?

Wired means the thermostat is connected to your boiler by a wire, like most ordinary room thermostats. If you already have a thermostat with a wire to the boiler, a wired smart thermostat usually simply takes over that spot and that wire.

Wireless means the sensor hangs loose on the wall or stands on a shelf, and communicates wirelessly with a receiver connected at the boiler. That is handy if there is no wire, or if your old thermostat is in an awkward spot, such as a cold hallway. A thermostat belongs in the room where you want to control the temperature, usually the living room.

One thermostat or room-by-room control?

A room thermostat controls the boiler based on the temperature in the room where it hangs. The other rooms get heat whenever the boiler runs, whether they need it or not. If you want a separate temperature and schedule per room, you need smart radiator thermostats that you fit on the radiators. With tado X you buy them separately or together with a thermostat in a Multi Room starter kit.

What else to look for

Suitable for your installation. Before buying, check whether the thermostat works with your boiler, district heating or (hybrid) heat pump. tado offers a compatibility check on its website.

Smart home integrations. The tado X range works over Thread and supports Matter, a standard that makes connecting to platforms such as Apple Home, Google Home and Alexa easier. If you are building a wider smart home, also read our buying guide to smart home hubs or start with the smart home beginner's guide.

tado Bedrade Slimme Thermostaat X Startpakket — Best overall, wired starter kit (€170-€200)

Best for most households with a wired thermostat: the tado Wired Smart Thermostat X Starter Kit, because it replaces your existing thermostat and immediately gives you a complete system you can expand later.

tado X is tado's newest product line. This second-generation starter kit contains the Wired Smart Thermostat X and the Bridge X. You then control the heating with the app: set schedules, adjust the temperature remotely and see when the heating is on. Later you can add radiator thermostats or a second zone to the same system.

Who it's for: anyone who wants to replace an existing wired room thermostat with a smart thermostat with a comprehensive app.

tado Draadloze Slimme Thermostaat X Startpakket — Best wireless starter kit (€190-€225)

Best for anyone who wants to place the thermostat freely: the tado Wireless Smart Thermostat X Starter Kit, because no wire from the thermostat to the boiler is needed.

This starter kit contains the Wireless Receiver X, which you connect at the boiler, and the Wireless Temperature Sensor X, which you mount or stand in the room where you actually want to measure the temperature. According to tado, a separate Bridge X is not needed because the receiver fills that role. That is handy if your old thermostat hangs in the hallway or there is no wire. The starter kit costs around €192, slightly more than the wired version.

Who it's for: homes without a thermostat wire or with a thermostat in an awkward spot.

tado Bedrade Slimme Thermostaat X Multi Room Startpakket — Best for room-by-room control (€300-€345)

Best for anyone who wants room-by-room control from the start: the tado Wired Smart Thermostat X Multi Room Starter Kit, because besides the wired thermostat you get two Smart Radiator Thermostats X.

With the radiator thermostats you can give, for example, the bedroom and the study their own temperature and schedule, separate from the living room. With tado's room-linking feature, the thermostat and the radiator thermostats work together, so the boiler only supplies heat when a room asks for it. The kit is also available with more radiator thermostats; this version with two is the entry point. If you prefer to buy the radiator thermostats separately later, you can also do that with the regular starter kit.

Who it's for: homes where rooms are used differently and you don't want the same temperature everywhere.

tado Bedrade Slimme Thermostaat X Uitbreiding — Best extension for a second zone (€110-€135)

Best for anyone who already has a tado X system: the tado Wired Smart Thermostat X Extension, because it lets you add an extra heating zone without buying another starter kit.

Note: this is not a starter kit. It only works as an addition to an existing tado X system. If your home has two wired zones, for example radiators downstairs and a separate underfloor heating zone, an extension lets you control each zone with its own thermostat in the same app. At around €114 it is cheaper than a starter kit, but only useful if you already have one.

Who it's for: existing tado X users with a second wired heating zone.

tado Draadloze Temperatuursensor X — Best standalone sensor (€90-€110)

Best for anyone with radiator thermostats who doesn't want to measure the temperature next to the radiator: the tado Wireless Temperature Sensor X, because you place it centrally in the room, so the Smart Radiator Thermostats X heat based on the actual room temperature.

Next to the radiator it is often warmer than on the sofa or at your desk. This sensor measures wherever you put it and shows the current temperature and humidity on its display. You can also use it to adjust the target temperature. It doesn't work on its own: you need a tado X starter kit or radiator thermostats from the X range.

Who it's for: tado X users with radiator thermostats in a room where the radiator sits in a cold or particularly warm spot.

Comparison table

Product	Type	Price indication
tado X Starter Kit wired	starter kit, wired, with Bridge X	around €173
tado X Starter Kit wireless	starter kit, wireless, with receiver	around €192
tado X Multi Room Starter Kit wired	starter kit, wired, 2 radiator thermostats	around €307
tado X Extension wired	extension, wired	around €114
tado Wireless Temperature Sensor X	standalone sensor, extension	around €96

Frequently asked questions about smart thermostats

Can I install a smart thermostat myself?

In many cases, yes. With a wired thermostat you usually connect the existing wire to the new thermostat, and tado guides you step by step in the app. If you are unsure about the wiring, if 230-volt work is involved or if you have a multi-zone installation, call in an installer.

Does a smart thermostat work with a heat pump?

That depends on the thermostat and the heat pump. A heat pump works best at a low, constant temperature and often has its own controls. So before buying, check with tado's compatibility check or your installer whether the combination works, and which features you can and can't use.

Do you save energy with a smart thermostat?

A smart thermostat doesn't save energy by itself, but it makes it easier to turn the heating down when nobody is home or everyone is asleep. How much that saves depends on your home, your boiler and your habits. If you already had a well-set programmable thermostat, the difference is smaller than if your heating is often on unnecessarily now.

Do I need a subscription for a smart thermostat?

For the basic functions, such as app control and schedules, tado doesn't require a subscription. Extra features, such as responding automatically to your location (geofencing), are part of tado's Auto-Assist, a paid subscription. Check before buying which features matter to you.

Can I control the temperature per room?

A room thermostat controls the temperature in the room where it hangs. To control each room, you need smart radiator thermostats that you fit on the radiators. With tado X you buy them separately or in the Multi Room starter kit, and they only work with other products from the X range.

Final thoughts

For most households, the tado Wired Smart Thermostat X Starter Kit is the best smart thermostat in this comparison: easy to install in place of your current thermostat and expandable later. Without a thermostat wire, choose the wireless starter kit, and if you want room-by-room control straight away, the Multi Room starter kit is the logical step. The extension adds a second zone and the standalone temperature sensor measures in the right spot. Always check in advance that the thermostat suits your boiler.