Thermostat replacement and installation cost

For professional installation, Trane lists hourly rates between $75 and $150. It also notes that you may find some thermostats for less than its table shows, and that the cost can be higher if the wiring needs to be changed.

• The thermostat. A basic model only holds one temperature. A programmable model follows a schedule. A smart model adds Wi-Fi, an app and often room sensors.
• Labor. A like-for-like swap on the same wall with good wiring is a short job. Most of the labor cost on a simple job is the minimum visit charge.
• Setup. Smart thermostats and multi-stage or heat pump systems need to be configured so the thermostat knows what equipment it controls. A wrong setting can run expensive backup heat when you do not need it.

• No C-wire. Most smart thermostats need a common wire for steady power. If your wall has no spare wire, the installer has to run new cable or fit an adapter at the furnace or air handler.
• Moving the thermostat. A new location means fishing wire through walls and patching the old spot.
• System type. Heat pumps, dual-fuel systems, two-stage equipment, zoning panels and humidifiers need a compatible thermostat and more setup time.
• Communicating systems. Some variable-speed systems only work fully with the manufacturer's own control. That limits your choice and raises the price.
• Line-voltage heat. Baseboard and wall heaters need a line-voltage thermostat installed by an electrician.

A blank or unresponsive thermostat is often a symptom of something else. Dead batteries, a tripped breaker, a furnace power switch that got bumped, a blown fuse on the furnace control board or a full condensate pan that tripped a safety switch can all shut the thermostat down. Replacing the thermostat fixes none of these.

Work through the safe checks on the thermostat not working page first. If the screen is still dead, ask the technician to confirm the cause before you pay for a new thermostat.

• The exact thermostat model and its price.
• Labor, and whether a service call fee is added.
• Any wiring work: a new C-wire, an adapter or a relocation.
• Setup for your equipment type, plus a test of heating, cooling and fan.
• Warranty on the thermostat and on the labor.

If you already bought a thermostat, ask whether the contractor will install customer-supplied equipment and whether their labor warranty still applies. A thermostat is never a reason to replace a furnace or AC. If a contractor moves the conversation from a thermostat to a new system, ask what test results support that. Other prices are in the HVAC cost guides.