The answer to 'how much to fix evaporator coil in Illinois' depends on several factors, but you can typically expect to pay between $300 to $1,500 to repair or replace an evaporator coil. The exact cost will depend on the size and complexity of your HVAC system, the location and accessibility of the coil, the cost of parts, and the labor rates in your local area.
Evaporator coil replacement is generally a job for a professional HVAC technician, as it requires specialized knowledge and equipment. Trying to DIY this repair can be dangerous and may void your HVAC system's warranty. To get an accurate estimate, it's best to have a local HVAC contractor inspect your system and provide a quote based on the specific work needed.