The best smart thermostat
We installed 8 smart thermostats in three homes with furnaces and heat pumps. The WarmWise 3 saved the most energy without sacrificing comfort.
Jake Morrison
Ryan Mitchell, editor-in-chief
September 1, 2026
12 weeks · 8 models
We choose products independently. We may earn a commission through links on this page; your price stays the same. Affiliate policy
In this guide+
Our picks at a glance
WarmWise 3
Controls the furnace with modulation and saved 11 percent on energy in our test.
Read the full review
Thermi Go
A simple smart thermostat with a clear app and no subscription.
Read the full review
WarmWise Pro
Also works with a heat pump and controls each room with separate vent sensors.
Read the full reviewPrices checked September 30, 2026. Prices may change.
Why you can trust us
Jake Morrison spent ten years as an HVAC technician and has tested tools and smart home products since 2023. For this guide we tested 8 models over 12 weeks in our test house. We bought most models ourselves; loaned units were returned after testing. Manufacturers don’t see our conclusions before publication.
Who is this for?
A smart thermostat adjusts the temperature to when you’re home. It saves the most if you have irregular working hours.
How we tested
We installed each thermostat ourselves and tracked energy use for twelve weeks, compared with a regular programmable thermostat. We also tested the app and integration with Google, Alexa and HomeKit.
Test setup in our test house in Columbus. Photo: HouseholdMe
Our full test methodTest results compared
| Model | Rank | Test score | Price from |
|---|---|---|---|
| WarmWise 3 | Our pick | 8.9 | $219 |
| Thermi Go | Budget pick | 7.9 | $119 |
| WarmWise Pro | Upgrade | 9.1 | $299 |
Test score based on our fixed weighting scheme. Price from: lowest price on September 30, 2026.
Frequently asked questions
Does a smart thermostat work with every HVAC system?+
Almost all modern systems work with it. Some models need a C-wire for continuous power.
How much do you really save?+
In our test, between 6 and 11 percent on energy compared with a programmable thermostat, depending on how often you’re away.
Jake spent ten years as an HVAC technician installing furnaces and heat pumps. Since 2023 he has tested tools and smart devices for HouseholdMe. He has renovated two houses himself.