The answer to 'how much to fix furnace in Illinois' is that the cost to repair a furnace can vary widely, typically ranging from $150 to $1,000 or more. The specific cost will depend on factors like the age and type of furnace, the nature of the repair needed, your location within Illinois, and the experience level of the HVAC technician.
Furnace repairs can involve anything from replacing a thermostat or fan motor to fixing a cracked heat exchanger. More complex issues like a complete furnace replacement can cost several thousand dollars. It's best to get quotes from local HVAC contractors to get an accurate estimate for your specific situation.