Smart thermostat buying guide
Updated: October 2026
You are looking at a combi, a system boiler, or a heat pump, and the amazon.co.uk results all look like one product. Some boxes contain a receiver that can call the boiler. Some contain only a wall head, and some contain radiator heads that never fire the boiler at all. This smart thermostat buying guide stops at those checks. The [smart home thermostat comparison](/hub/thermostats/smart-home-thermostat) holds the full table, the stars, and the prices. Know which part has to be in the box before a 4.7-star line is allowed to matter. Peter F. used these amazon.co.uk listings on 16 October 2026 and did not run a lab test. A purchase through our links can earn a commission at no extra cost to you.
You are looking at a combi, a system boiler, or a heat pump, and the amazon.co.uk results all look like one product. Some boxes contain a receiver that can call the boiler.
You are looking at a combi, a system boiler, or a heat pump, and the amazon.co.uk results all look like one product. Some boxes contain a receiver that can call the boiler. Some contain only a wall head, and some contain radiator heads that never fire the boiler at all. This smart thermostat buying guide stops at those checks. The smart home thermostat comparison holds the full table, the stars, and the prices. Know which part has to be in the box before a 4.7-star line is allowed to matter. Peter F. used these amazon.co.uk listings on 16 October 2026 and did not run a lab test. A purchase through our links can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | In the box | Hot water | Network | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  tado tado V3+ wireless starter kit | Sensor, receiver, Internet Bridge, UK adapter | Title says programmer with hot water control | Wi-Fi | 9.0 | about £57.50 | View offer |
 Hive Hive thermostat with Nano 3 hub | Nano 3 hub | Heating only | Wi-Fi | 8.8 | about £164.99 | View offer | |
 tado tado Wireless Smart Thermostat X starter | Wireless Receiver X and room sensor | App listing says yes; a review says Alexa does heating only | Wi-Fi and Matter | 8.8 | about £129.99 | View offer |
On this page
What you are actually buying
Four jobs sit under the same search. A starter kit puts the room control and the part that talks to the boiler in one parcel: a receiver, a bridge, or a hub. An add-on is a second wall head for a system you already run. A radiator head replaces the dial on one radiator and still needs something else to call the boiler. A Zigbee wall thermostat can switch a boiler only after it joins a coordinator that was not in that box. The wireless tado X starter, at about £129.99, is the first kind: Wireless Receiver X and the room sensor, and the listing says no extra hub is required. The wired tado X add-on, at about £79.99, is the second: reviews and the listing agree you need a Bridge X or another Thread border router, and that part is not included. The tado X radiator trio, at about £159.08, is heads and adapters with no boiler receiver. The SONOFF TP-WGZBA, at about £34.20, is Zigbee 3.0 with a dry contact and no hub. Treat the included-components line as the product. A photo of a round dial does not tell you whether the boiler will hear it.
Five checks before the price
Name the heat source before the brand. A combi needs a heating call. A system or regular boiler with a cylinder needs a control that can schedule that cylinder, or you keep the existing hot-water channel. A heat pump or wet underfloor loop is a different terminal job from a combi relay. The Hive kit, at about £164.99, says heating only and says it is not for a conventional boiler that needs separate heating and hot water control. That sentence matches many combis and rejects a cylinder. Then ask what radio part is in the parcel. Hive’s title includes the Nano 3 hub. The V3+ starter, at about £57.50, includes the Internet Bridge, a UK adapter, and an Ethernet cable. The wireless tado X starter says the receiver is enough. The wired add-on and both radiator products do not include that path. Hot water is the third check: a heating-only listing is a fit if you only heat rooms, and it is not a second channel you can invent in the app. OpenTherm is the fourth. Several listings name OpenTherm and a relay, which helps only when the boiler manual already lists those terminals. Generation is the fifth. tado says tado X products are not compatible with tado V3+ or older. Matter on an X listing does not cross that gap.
What the controls can and cannot save
The Energy Saving Trust describes a programmer, a room thermostat, and thermostatic radiator valves as the usual heating controls, and it puts the saving from fitting the missing controls at about £100 a year in Great Britain. That figure is for getting basic control in place. It is not a promise that swapping one smart brand for another takes £100 off a bill that is already timed and already has a room stat. Brand pages often print a larger up-to percentage. Those lines are the maker’s claim. Which? makes the same caution: the saving is less clear if those controls already exist. This comparison is not quoting a Which? score. On the tado X starter, AI Assist is £3.99 a month or £29.99 a year, and reviews say geofencing and open-window detection sit behind that fee. The V3+ listing prices Auto-Assist at £3.99 a month, and reviews say ordinary schedules work without it. The Hive listing does not print a subscription. A cheap shelf price plus a coordinator you still have to buy can cost more than the £57.50 V3+ kit that already includes the bridge. Boiler Plus in England applies when a boiler is installed or replaced in an existing dwelling, with an extra measure on a combi. It is not a Scotland-wide order, and it is not a reason to retrofit every combi that is already running.
Which kit type fits which home
If you want a current tado X system and the receiver must arrive with the sensor, the wireless starter is the box that states that. If you are replacing a wired stat and you want Bridge X in the parcel, the wired X 2nd gen starter includes it, at about £156.44. The title says wired and the included-components line says wireless, so check the live contents. If you already run tado X and you only need another room or a wet underfloor zone, the £79.99 add-on is the smaller purchase, and the wrong purchase if this is your first thermostat. If the budget is the constraint and you will stay on the previous generation, the V3+ starter is the complete kit. Skip it if you plan to buy X heads. If the boiler is a combi and you want the hub in the box with a heating-only statement, Hive is the one that says so, at a higher shelf price. If you already run Home Assistant or another Zigbee coordinator, the SONOFF wall stat can be the heating call, and the SONOFF TRV Gen2 at about £29.91 can be one radiator. Neither is the first buy for a Wi-Fi-only house. Radiator heads alone leave the boiler on its old control. The best smart thermostat UK page names a top pick and a best value from this same set.
Common questions
Do I need a different kit for a combi, a system boiler, or a heat pump?
A combi usually needs one heating channel, because hot water is made when you open the tap. A system or regular boiler with a cylinder needs hot-water scheduling as well, and the Hive kit here says it does not do that. The tado listings that mention a heat pump or wet underfloor are the wireless X starter, the wired add-on, and the wired X starter’s boiler-link line. Match the manual’s terminals before you treat those words as a guarantee.
Does the box include the receiver, the hub, or neither?
Read the included-components line, not the lifestyle photo. The wireless tado X starter includes Wireless Receiver X. The V3+ starter includes the Internet Bridge and the receiver. Hive includes the Nano 3 hub. The wired tado add-on, the radiator trio, the SONOFF wall stat, and the SONOFF TRV do not include the hub or the boiler receiver you would need to start from nothing.
Is OpenTherm on the listing the same as OpenTherm on my boiler?
Only if the boiler supports it. The thermostat can offer OpenTherm and a plain relay, which is what several tado listings and the Hive combi kit state. If your boiler manual specifies a manufacturer bus, that printed OpenTherm line does not create the connection. The relay fallback is the part to confirm with the existing wiring.
Can I add tado X heads to a V3+ bridge?
No. tado’s compatibility note, and the X listings in this comparison, say X products do not work with V3+ or older. The £57.50 V3+ kit is a full starter for that older system. It is a dead end if the next purchase is an X radiator head.
Is a £30 Zigbee thermostat a starter if I only have Wi-Fi?
No. The SONOFF TP-WGZBA is Zigbee 3.0 at about £34.20, with 4.7 from 38 ratings. Reviews join it through Home Assistant and a coordinator. There is no Wi-Fi setup on the listing, and the hub is not in the box. Wi-Fi alone leaves it silent.
What saving can I quote without using the brand’s percent?
Use the Energy Saving Trust figure with its limit: about £100 a year in Great Britain when you fit the programmer, room thermostat, and radiator valves that were missing. Do not turn a maker’s up-to line into your bill forecast. If you already have a timer and a room stat, the extra from a smarter app is smaller, and a £3.99 monthly automation plan can eat the difference.
Related pages
Sources
Public UK sources for Energy Saving Trust savings, Boiler Plus in England, Part L, and Gas Safe. Listings are the amazon.co.uk captures for these eight ASINs on 16 October 2026. Prices on amazon.co.uk move.
- Energy Saving Trust, thermostats and heating controls (retrieved 16 October 2026)
- Energy Saving Trust, take control of your heating (retrieved 16 October 2026)
- Boiler Plus circular (2018) (retrieved 16 October 2026)
- SI 2026/335 (retrieved 16 October 2026)
- Approved Document L (2026) (retrieved 16 October 2026)
- Gas Safe Register, home improvements (retrieved 16 October 2026)
- Hive shop, thermostat (retrieved 16 October 2026)
- tado compatibility (retrieved 16 October 2026)