The answer to 'how much to fix thermostat in Illinois' is that the cost can vary significantly depending on several factors. Generally, the typical range for thermostat repair in Illinois is between $75 to $300, but the exact price will depend on the type of thermostat, the complexity of the repair, and your location within the state.
Some key factors that influence the cost include the age and model of the thermostat, whether it needs to be replaced or can be repaired, the accessibility of the thermostat, and the labor rates of HVAC technicians in your area. It's important to get multiple quotes from local HVAC companies to ensure you get a fair price for the repair.