In addition to the service fee, you’ll also have to factor in the cost of labor and parts. Some repairs, such as fixing a refrigerant leak, will cost anywhere between $200 and $1,500. Smaller problems like fuses and circuit breakers will run between $50 and $200.Depending on the HVAC model you have, a new thermostat can cost between $80 and $300.Additionally, you can also contact an HVAC technician for routine maintenance checkups and filter replacements. Your HVAC technician may offer a yearly rate which includes two or three pre-paid visits at a discounted fee.ost of a Service Call. The cost of a service call depends on several factors. Most HVAC technicians will charge a flat rate just to come to your home and examine your HVAC system.