Repair  Cost Range Refrigerant Leak $200 - $1,500+ Compressor Replacement $1,000 to $2,500+ Fan and Motor Repair $100 - $800+ Ignition or Pilot Control $100 - $600+ Heat Exchanger Replacement $1,500 - $3,500+ Thermostat Repair or Replacement $50 - $300+ Air Duct Cleaning or Repair Costs $300 - $1,500+ Ventilation Fan Replacement $100 - $800+ Improving Indoor Air Quality $50 - $2,500+