How Much Does Thermostat Installation Cost? [2026 Data]

Thermostat installation runs $75–$350. Simple replacements with compatible wiring cost $75–$150. Smart thermostats (Nest, Ecobee) run $150–$350 installed.

C-wire installation adds $100–$250 if your system lacks one. Multi-zone systems cost more for each zone.

DIY is possible for basic swaps if you have a C-wire. Pros ensure correct programming and compatibility.