June 28, 2022

Many of the best smart thermostats require a C wire (“common” wire) to provide enough power for LED displays and Wi-Fi-powered advanced functions. That’s why some homeowners need smart thermostats without a C wire requirement. The thermostats below run on low power or ship with DIY power adapters that anyone can install. Here are our favorite picks that’ll help you avoid hiring a professional to rewire your home — just keep in mind that some thermostats have more reliable performance without a C wire than others.

Ditch the professional and consider these smart thermostats

No C wire? No problem (mostly)!

The majority of older homes and heating/cooling systems won’t have a C wire. Since you may not be comfortable installing the wire yourself or paying for an electrician, these smart thermostats without a C wire will still reduce your energy bills. Some use batteries that you’ll have to keep replacing, while others require a power extension kit that will still necessitate some simple wiring on your part. Many of these are among the best smart thermostats, so you can rest assured that a C-wire requirement doesn’t equate to better quality.

See also  Ecobee's new thermostats can sense you through walls and measure air quality