Best Thermostats 2026

Check your existing wiring before buying. Smart thermostats highly prefer a 'C-wire' (Common wire) for continuous power, otherwise they must steal power or rely on disposable batteries.

A thermostat typically lasts 10 to 15 years for programmable models and longer for simple mechanical models. Smart thermostats may have shorter lifespans of 5 to 10 years due to software obsolescence and battery degradation. Signs of end-of-life include unresponsive controls, incorrect temperature readings, the HVAC system not responding to setting changes, and Wi-Fi connectivity issues on smart models.

Top-rated thermostats brands include Google, ecobee, GE, Honeywell, Scotch and more. Covala Shopping tracks 17 thermostats from 6+ brands.

The device itself costs pennies to power. The true 'cost' of a smart thermostat is the investment return; a properly programmed one saves 10-15% on annual HVAC costs.