Best Smart Thermostats for Heat Pumps UK 2026

Why Heat Pumps Need Different Thermostats

Your old gas boiler was simple. The thermostat said "heat on", the boiler sent hot water round the radiators, and it switched off when the room hit temperature. On/off control worked fine because gas boilers are built for short, aggressive burn cycles.

Heat pumps are fundamentally different. They work best running gently for hours, sometimes all day, at a low flow temperature (usually 35 to 55C). When a basic thermostat forces a heat pump to cycle on and off, it's like driving by flooring the accelerator and then slamming on the brakes. You'll get there, but you'll use more fuel.

The magic word is modulation: running the heat pump at the flow temperature the house needs right now. The protocol most smart thermostats use for that is OpenTherm, and they use it with boilers. Drayton says plainly that Wiser "interfaces with heat pumps via On/Off controls", and Hive's OpenTherm is "for compatible combi boilers only". Don't buy a thermostat on the OpenTherm promise; ask your installer whether your heat pump takes OpenTherm from a room thermostat at all.

The other key idea is weather compensation, which sets the flow temperature from the outdoor temperature: barely ticking over on a mild day, working harder on a frosty night. Modern heat pumps do this themselves with their own outdoor sensor. A third-party thermostat that overrides it with on/off control makes things worse.

Check Your Heat Pump First

Before spending money on a thermostat, find out what your heat pump already does. Your existing controller is probably handling weather compensation perfectly well. If so, you only need a smart thermostat for convenience (app control and scheduling), not for efficiency.

Our Picks

The tado Smart Thermostat X is a polished room thermostat. On a boiler it can modulate over OpenTherm; on a heat pump, on its own, it's an on/off switch with a very good app unless the heat pump takes OpenTherm. Where tado gets interesting for heat pumps is its separate Heat Pump Optimizer X, which tado says "works with your heat pump without replacing the control unit" and lists for brands such as Panasonic, Daikin, Atlantic, Vaillant, Saunier Duval and Fujitsu (tado is Panasonic's partner for smart heat pump control). It doesn't need a tado thermostat, though tado says adding its room thermostats gives "greater savings". Check your exact model in tado's compatibility checker before you buy.

The X uses Matter and Thread, so it works with Alexa, Google Home and Apple Home, and tado makes matching smart radiator thermostats if you want per-room control.

The catch: the automatic features sit behind a subscription. tado's AI Assist costs £3.99 a month, with an annual plan it says is 37% cheaper, so about £30 a year on the annual plan, or £48 paying monthly. Geofencing, pre-heating before you get home, open window detection and holiday mode are all in that tier; remote control and the smart schedule are in the free app. The Heat Pump Optimizer's own extra, Balance, is £5.99 a month. tado says the Optimizer saves 22% on average, but its footnote says that's from data "averaged across all tado° customers", not just heat pump homes.

If tado is the premium option, Drayton Wiser is the smart choice for people who'd rather pay nothing ongoing. There are no subscription fees, and Drayton gives a 3 year warranty. Check the live price on the card, because the Wiser thermostat kit drifts in and out of stock on Amazon.

Be clear about what it does with a heat pump: Drayton's own spec says it "interfaces with heat pumps via On/Off controls", so its OpenTherm support is for boilers. Drayton also lists an Airzone Aidoo Pro integration that connects Wiser directly to compatible air-to-water heat pumps, for heating and hot water from the Wiser app; ask your installer whether yours is one. The app does scheduling with Eco, Comfort and Away modes. The real strength is the radiator valve range: each room with a Wiser valve becomes its own zone, so the living room can sit at 21C while the bedrooms stay at 17C. With a heat pump that kind of zoning is worth having.

Drayton is owned by Schneider Electric.

Who should buy this: anyone who wants smart scheduling and per-room control without a subscription. If you're kitting out several rooms with valves, the missing subscription is the deciding factor.

Homely is the odd one out, and that's exactly why it's interesting. The room thermostats here grew up controlling boilers, and the sensoCOMFORT is Vaillant's own; Homely calls itself "the smart controller heat pumps deserve". It connects to the heat pump directly rather than over a thermostat wire, and it runs the heating for you: flow temperature, scheduling and, on a time-of-use tariff, moving heat into the cheap hours.

Its compatibility list covers Airwell, Clivet, Daikin, Ebac, Grant, Ideal, LG, Midea, Mitsubishi, Nordis, Riello, Samsung, Trianco and Worcester Bosch. Vaillant isn't on it.

A note on the savings claim. Homely's site gives no savings percentage or pound figure. It says the device "typically pays for itself within one year", without the sum behind it, plus installation in under 45 minutes with no weather compensation curves to set, remote monitoring by your installer, and about 2 tonnes of CO2 avoided a year. With no figure to check, we're not printing one.

What it costs to run: the basic Smart mode costs nothing a year and already adapts to your electricity tariff; Homely says it's best on a single-rate tariff. Smart+, which Homely says is best on a multi-rate tariff, is £25 a year. Homely doesn't publish the price of the device; it comes through your installer, and EDF offers it with its heat pump quotes.

The installer dashboard is a genuinely clever touch. Your heating engineer can see if the flow temperature is too high or the system is cycling, and fix it without a visit.

Who should buy this: anyone with a listed heat pump who wants it properly optimised without learning what a weather compensation curve is. It's the closest thing to a "just make it work properly" button.

The Hive Thermostat Mini is a good, cheap thermostat for a boiler: Hive sells it for £79, plus £80 for a hub if you haven't got one, and it works without a subscription (Hive+ is optional).

For a heat pump, check before you buy it. Hive lists it for gas, LPG, oil and some electric boilers, and says its engineers can't install a Hive thermostat on heat pumps: "We are yet to complete our testing on these systems and therefore can't yet guarantee compatibility." Its OpenTherm is for combi boilers only. If your installer is happy to wire it as a simple on/off switch, with the heat pump's own weather compensation left in charge, it gives you scheduling and app control. If not, Drayton Wiser is the no-subscription choice that Drayton says works with heat pumps.

If your house already runs on Google Home, the Nest Learning Thermostat (3rd gen) is the natural choice. It learns your routine and builds a heating programme itself, and the display is gorgeous.

Credit where it's due: the 3rd gen Learning Thermostat and the Nest Thermostat E do support OpenTherm, and Google describes using it to modulate a boiler. An earlier version of this guide said Nest was relay-only, which was wrong. With a heat pump, though, the same rule applies as for every room thermostat here: unless your heat pump takes OpenTherm, it's switching it on and off.

The other downside: there are no Nest radiator valves. If you want per-room control (and with a heat pump you should), you'll need third-party valves that may not integrate cleanly. tado and Wiser have their own valve ranges, which is a real practical advantage.

Check the live price on the card before you fall for it. You're paying for the hardware and the ecosystem, not for anything that makes a heat pump run better.

Who should buy this: people already deep in Google Home who want a beautiful thermostat and have looked at that price with clear eyes.

It only works with one brand, which is why it's easy to overlook. But if you have a Vaillant heat pump, the sensoCOMFORT is the control to have.

It's Vaillant's own weather compensation control, it works with all Vaillant heating appliances including the heat pumps, and with the myVAILLANT connect gateway you get the myVAILLANT app for remote control. Because it's part of the Vaillant system rather than a thermostat wired to it, it sets the flow temperature properly, which a third-party room thermostat on a Vaillant can't. Homely doesn't list Vaillant; tado lists Vaillant for its Heat Pump Optimizer X if you want tado's app.

Ask your installer to include and commission it with the heat pump. The app is functional rather than slick, but it's the control Vaillant designed for its own system.

If you have a Vaillant aroTHERM plus, use the sensoCOMFORT.

Side-by-Side Comparison

The Real Question: Do You Even Need One?

If your heat pump was fitted by a competent MCS installer, the manufacturer's own controller with properly set weather compensation will probably run it more efficiently than any room thermostat switching it on and off.

The genuine reasons to add something are:

• App control and smart scheduling: convenience, not efficiency.
• Geofencing: turning the heating down when everyone's out. No independent UK body publishes a figure for it on its own, so treat any percentage you see (including the makers' own) as a best case.
• Per-room control through smart TRVs: the biggest real win, and you need a hub to coordinate them.
• Direct heat pump control from Homely or tado's Optimizer, if your brand is supported.
• You're not sure the weather compensation curve was set properly. Before buying anything, ask your installer to check it: it's the setting that decides how hot the heat pump runs.

If none of those apply, save your money. A properly configured manufacturer controller beats a badly configured smart thermostat every time.

What the Evidence Says About Savings

Our previous version of this guide had one, with percentages for each type of control that no source backed up, so we've taken it out. Here's what the published evidence actually says:

• Heating controls in general: the Energy Saving Trust says installing and using heating controls effectively (programmer, thermostat and radiator valves) could save around £100 a year in Great Britain and £110 in Northern Ireland.
• Radiator valves with a heat pump: Drayton cites independent BEAMA testing that found TRVs and smart TRVs work with air source heat pumps, saving 6 to 8% without hurting the heat pump's performance.
• The makers' own figures: tado says 22% on average across its customers; Homely no longer publishes a figure. Treat both as marketing, not measurements.

So the first move isn't buying a thermostat. It's asking your installer to check the weather compensation curve.

Smart TRVs: The Real Efficiency Multiplier

Where the published evidence points, beyond the thermostat, is smart TRVs: valves on each radiator so you stop heating rooms nobody's in. If you're out all day and only use the living room in the evening, why are three bedrooms being heated to 21C?

With a heat pump this matters even more, because every unnecessary degree costs electricity, and the BEAMA testing above is the one heat-pump-specific number to work from: 6 to 8%. tado and Drayton Wiser both make their own valves to go with their thermostats; Nest doesn't.

See our full smart TRV comparison guide for which valves work best with which thermostats.

Total System Cost: What You'll Actually Spend

A thermostat on its own is only part of the picture. Prices move, so take the live price on each card as the real one. What differs between the systems is mostly what you pay after you've bought them:

• tado: thermostat plus valves, and then £30 a year on the annual plan, or £48 paying monthly for AI Assist if you want geofencing; £5.99 a month for Balance with the Heat Pump Optimizer
• Drayton Wiser: thermostat kit plus valves, no subscription fees
• Homely: the device on your installer's quote, then free in Smart mode or £25 a year for Smart+ (no radiator valves; it works on the heat pump instead)
• Hive Mini: £79 from Hive, plus £80 for a hub if you need one; Hive+ optional. Only if your installer will wire it to the heat pump (above)
• Nest Learning Thermostat: check the live price, and third-party valves are extra and may not integrate cleanly
• Vaillant sensoCOMFORT: through your Vaillant installer (no valve range of its own)

The valves are DIY: they screw onto the valve bodies you already have. Have your heating engineer wire the thermostat itself if you're not confident, and with a heat pump make sure they wire it so the heat pump's weather compensation stays in charge.

On payback, the only published number to work from is the Energy Saving Trust's £100 a year in Great Britain for a complete set of heating controls. A system with a thermostat and four valves takes a few heating seasons to pay back even if you get all of that, and longer with a subscription on top. Neither tado nor Wiser is a bad buy, but neither is a money-maker: buy them because you want the control, not because a spreadsheet told you to.

A Note on Installation

The Hive and Nest are DIY-friendly if you're comfortable with basic wiring. With a heat pump, though, it's worth asking your installer to connect any room thermostat, because how it's wired decides whether the heat pump's own weather compensation still runs the show.

Homely is fitted by an installer, and the sensoCOMFORT should be set up by your Vaillant installer as part of commissioning the heat pump. tado says the Heat Pump Optimizer X is a self-install with a step-by-step guide in its app.

For more on cutting your heat pump bills, see our running costs guide. Still choosing a heat pump? Our best heat pumps guide covers the top brands. And our heat pump savings calculator estimates what you'll actually spend.