Thermostat Not Working

Blank screen, unresponsive, or not controlling your system — here's what's usually behind it.

Dead or low batteries

The most common cause for battery-powered thermostats — worth checking first, even on smart thermostats with battery backup.

Tripped breaker or blown fuse

Hardwired thermostats rely on power from your HVAC system — a tripped breaker affecting the system will also affect the thermostat.

Wiring issue

Loose or miswired connections, especially after a DIY thermostat swap, are a common cause of a thermostat that won't communicate with the system.

Wi-Fi or app connectivity issue (smart thermostats)

The thermostat may be functioning locally but not syncing with the app — worth checking if the physical display still works even if the app doesn't.

Failed thermostat

Like any electronic device, thermostats can simply fail with age — usually a straightforward replacement.

Frequently asked questions

Can I install a new thermostat myself?

Many homeowners do for simple swaps, but incorrect wiring can cause system issues or safety problems. We offer smart thermostat installation if you'd rather have it done right the first time.

My smart thermostat app isn't working — is that the same as the thermostat being broken?

Not necessarily — check if the physical display still shows temperature and responds to manual adjustment. If so, it's likely a connectivity issue, not a hardware failure.

See our full Smart Thermostat service or browse other common symptoms.