Best Smart Thermostats for Heat Pumps of 2026

Four wires at the wall and no C terminal is the most common reason a heat pump owner gives up on a smart thermostat, and the Sensi is our budget answer to it. It runs on the two AA batteries in the box, so there's no adapter to buy and no fifth wire to fish through the wall. It also fits the footprint of the thermostat you're replacing, which means no patching and painting around a smaller plate.

The rest is deliberately plain: buttons instead of a touchscreen, a 5-inch display, and an app that handles scheduling, usage reports, and a maintenance nudge when the filter is due. It works with Alexa, Google Assistant, HomeKit, and SmartThings, and Sensi's promise not to sell your personal information is a small thing that matters more than it used to.

We rate it the value pick rather than the default for one reason: the radio is the weak part of an otherwise easy sell. When the connection holds, this is the simplest thermostat in the group to live with and one of the easiest to install — the built-in level is a genuinely nice touch — but a thermostat that keeps falling off the network is a dumb thermostat with a good app. With the router in the next room and modest expectations, the savings are real.

The battery-only install is also the one to watch. Short cycling can show up in that configuration, so give it a week before you trust the schedule you built, and land the C wire if your wall has one to spare.

This is the one we point at when the heat pump has a gas furnace behind it. Staging up to 3 heat and 2 cool is more than anything else in this group offers, and it's what a two-stage heat pump with a backup furnace asks for: the thermostat has to run the compressor stages, call for backup heat when it should, and stay out of the furnace's way when it shouldn't. Under-buying here is how a system ends up leaning on the wrong heat source all winter.

The trade-off is that this is a contractor's thermostat. It needs a C wire, the interface is a touchpad with menus organized for whoever commissioned the system, and remote control runs through Honeywell's connected-service platform rather than the polished consumer apps elsewhere on this page. What you get for that is hardware that feels like it belongs in a mechanical room rather than a hallway, and a record with the people who install HVAC for a living.

One condition is worth knowing before you decide between this and a cheaper pick: Honeywell's five-year manufacturer coverage applies with proof of professional installation. Have it installed, keep the invoice, and this becomes the best-protected thermostat in the group by a wide margin.

The 4th-gen Nest is the one people notice. The polished ring, the larger display, the way the screen wakes as you walk past — it's the only thermostat here a guest would comment on, and if it's going in a hallway rather than a utility closet, that counts for something.

This bundle adds the Nest Temperature Sensor, and for a heat pump house we think that's the more useful half. A bedroom over the garage that never matches the hallway is the classic heat pump complaint, and the sensor lets the thermostat average the two rooms or favor the one you're actually in. Heat pump is on the compatibility list, and Nest says most homes won't need a C wire.

Two things keep it off the top spot for us. The 4th gen lives in the Google Home app and doesn't appear in the older Nest app, which is a real adjustment if you're upgrading from a previous Nest. And the premium buys the finish and the sensor rather than more heat pump capability, so what you're paying for is how it looks and where it measures. Calibrate it against a room thermometer in the first week — a few of these run a couple of degrees off, and that's the sort of thing you want to find out in October rather than January.

Think of the Premium as our top pick with a sensor in the box, a metal body, and Alexa built into the unit itself. The sensor is the part a heat pump owner should care about: it goes in the room that never matches the thermostat's reading, and the system works from that room instead of the hallway. Bought separately, that sensor is a meaningful chunk of the price difference.

The extras are real but quirkier than the price suggests. You can stream a video doorbell on the screen and ask Alexa to play music from a wall in your hallway, which is either delightful or beside the point depending on your house, and the air quality readout is a pleasant bonus rather than a reason to buy. The 95% compatibility figure is the highest in this group, and the Power Extender Kit is still included for a wall without a C wire.

Whether it's worth the step up depends entirely on the house. If two rooms disagree all winter, the bundled sensor makes this the cheaper way to solve it and the Premium makes sense. If your system is straightforward and you just want the heat pump handled properly, the Enhanced does the same job and takes a sensor later — and this is the pick on the page we're least sure of over five years, which is a strange thing to pay more for.