Best HVAC Contractors in St. Louis, MO

HVAC service calls typically range from $75–$200 for diagnostics. AC repair averages $150–$650, while a full AC unit replacement runs $3,500–$7,500. Furnace repair costs $100–$500 on average. Preventive maintenance plans typically cost $150–$300/year.

HVAC contractors must hold a state-issued mechanical contractor license in most states. They should also be EPA Section 608 certified for handling refrigerants. Some states require separate licenses for residential and commercial work.

• Are you licensed and EPA certified?
• Do you offer emergency/after-hours service?
• What brands do you install and service?
• Do you offer maintenance plans?
• What is the warranty on parts and labor?

Schedule annual maintenance before peak season (spring for AC, fall for heating). A well-maintained system lasts 15–20 years. When getting quotes for replacement, make sure the contractor does a proper load calculation — don't just match the old unit size.