The old thermostat had a little dial that turned stiffly and a number that was more of a suggestion. Ben unscrewed it from the hallway wall on a Saturday in early June, and underneath was a rectangle of paint two shades darker than the rest of the hall, the color the house must have been in about 2005. We patched that later. The new thermostat went up that afternoon, and after the rebate from our utility it cost us $119.
It has been about six weeks, through the stretch of July where the heat index sits above a hundred most afternoons and the air outside feels like a damp towel. People keep asking whether it was worth it. My honest answer is a qualified yes, with a few things I wish someone had told me first.
What a thermostat can and cannot do
This was the part I had backwards. I half expected the new thermostat to lower our bills by itself, the way a new appliance sometimes does. It cannot. It only decides when the heat pump runs and how hard. If the house leaks cool air, a smarter schedule just decides more cleverly when to waste it.
That is why I am glad we did it last instead of first. Our free home energy audit in May 2025 found leaky ducts in the attic and thin insulation up there. We had the ducts sealed that July for $380 and the attic insulation topped up last November for $1,450. The heat pump got a service in April, a cleaned coil and a new capacitor, for $165 total. By the time the thermostat went in, the house could actually hold the temperature we asked of it.
If I were starting over in a house like ours, a 1958 brick ranch with the ducts in a hot attic, I would still put the thermostat at the end of that list.
What it does well in heat like ours
A few features turned out to matter much more than I expected.
Gentle schedules instead of big swings
I used to think the trick was to let the house get hot while we were out and cool it down fast later. In real South Carolina heat that backfires. When the house climbs to 84 by late afternoon, the heat pump runs flat out for hours trying to pull it back down, right during the hottest, most expensive part of the day. Now the schedule only lets it drift up a couple of degrees, and it starts easing back down before we need it.
Watching the humidity
The display shows indoor humidity, which our old dial never did. On sticky days it reads 55 to 58 percent inside, and that number explains a lot. A room at 77 degrees and 50 percent humidity feels fine; the same room at 62 percent feels clammy. We keep the ceiling fans running in whatever room we are in and leave the setpoint where it is, rather than chasing comfort by dropping the temperature.
Seeing the run time
The app shows how many hours the system ran each day. On the hottest afternoon so far, a day with a heat index of 108, it ran a little over fourteen hours. On a cloudy day with a breeze, about eight. Seeing that made me close the blackout curtains on the west side by lunchtime, which we had gotten lazy about.
What did not work
- The "away" sensing. It decided we were gone on a rainy Saturday while all three of us were home playing cards at the kitchen table, and again a few days later. We turned that feature off and use a plain schedule.
- Remote fiddling. For the first week I adjusted it from my phone constantly, a degree here, a degree there. That is the opposite of the point. I now try not to touch it for days at a time.
- Expectations of instant savings. Our June bill was lower than last June's, but so much else changed in the past year that I cannot honestly credit the thermostat with any particular dollar amount.
So, is it worth it?
For us, at $119, yes, mostly for the information and the steadier schedule. I would not pay full price for it ahead of sealing ducts or adding insulation, and I would not expect it to fix a house that cannot hold its cool. The worst bill we ever had was last August, $312, and I will be watching this August's closely. I will report back once it comes, with the caveat that weather and luck always get a vote.
Tonight it is 91 outside at six o'clock, the cicadas are going in the pecans, and the little screen in the hall says 77. Lila is lying on the cool hardwood floor of the living room under the fan with Pepper, both of them perfectly content. That might be the best review I can give.
