Checklist for Hiring an HVAC Contractor — What to Verify Before You Sign

Licensing requirements vary by state, but most require HVAC contractors to pass exams covering mechanical codes, refrigerant handling, and electrical work. Ask for the license number and verify it online through your state's contractor licensing board. An unlicensed contractor means no regulatory oversight, no bond protection, and your homeowner's insurance may deny claims for work done without a permit.

Ask for a certificate of insurance and verify it's current — not expired. General liability covers damage to your property during the work. If an uninsured contractor's employee drops a compressor through your ceiling, you're filing on your own homeowner's policy. Call the insurance company listed on the certificate to confirm the policy is active.

Workers' comp covers the contractor's employees if they're injured on your property. Without it, an injured worker could file a claim against your homeowner's insurance. This is especially important for installation work involving rooftop units, attic work, or heavy equipment. Ask for proof and verify it's current.

Federal law requires anyone who handles refrigerants to hold EPA 608 certification. This applies to any work involving charging, recovering, or repairing refrigerant systems. The certification card should list the technician's name and certification type (Universal covers all equipment). A contractor without this certification is operating illegally.

Three estimates give you a realistic price range and help identify outliers. The lowest bid isn't necessarily the best — an unusually low estimate often means the contractor is cutting corners on materials, skipping permits, or planning to upsell once work begins. Compare estimates line by line: equipment model numbers, labor hours, materials, permits, and warranty terms should all be itemized.

A proposal that says 'Carrier 3-ton AC' is incomplete. You need the full model number to verify the efficiency rating, warranty terms, and price. Without model numbers, a contractor can substitute lower-tier equipment at the same price. Compare the quoted model numbers across your three estimates to ensure you're comparing equivalent equipment.

Most HVAC installations require a mechanical permit. The contractor should pull the permit — not you. If a contractor suggests skipping the permit to 'save you money,' walk away. Unpermitted work creates problems at home sale inspections, voids manufacturer warranties, and means no municipal inspection to catch code violations.

A Manual J calculation determines the correct equipment size for your home based on square footage, insulation, windows, orientation, and climate zone. A contractor who sizes equipment based on 'rule of thumb' or 'one ton per 500 square feet' is guessing — and oversized systems short-cycle, undersized systems can't keep up. Demand a load calculation for any equipment replacement. It takes 30–60 minutes and is worth every penny.

Look at Google Business reviews, BBB complaints, and Yelp. Focus on reviews that describe specific work quality, communication, and problem resolution — not just star ratings. A contractor with 4.5 stars and 200 reviews is more reliable than one with 5 stars and 12 reviews. Pay attention to how the company responds to negative reviews — defensiveness is a red flag.

If you need a full system replacement, ask for references from replacement jobs — not tune-up customers. Call the references and ask: Was the work completed on schedule? Were there surprise charges? How did they handle problems? Would you hire them again? Most homeowners are happy to share their experience.

A physical business location indicates an established operation with overhead, inventory, and accountability. Contractors operating from a truck with a cell phone number can disappear when warranty issues arise. Google the address to confirm it's a real business location, not a virtual office or residential address.

The manufacturer's warranty covers the equipment (typically 5–10 years for parts). The contractor's labor warranty covers the installation work. A reputable contractor offers at least 1–2 years of labor warranty. Get this in writing as part of the contract — verbal promises are unenforceable. Some contractors offer extended labor warranties for an additional fee, which can be worth it for complex installations.

Most manufacturers require warranty registration within 60–90 days of installation to activate the full warranty period. Without registration, the warranty defaults to a shorter base period (often 5 years instead of 10). The contractor should handle this registration — ask for confirmation that it's been done after installation.

The first heating or cooling season after installation often reveals issues: a zone that doesn't heat evenly, a duct connection that whistles, a drain that backs up. A good contractor addresses these callbacks promptly at no charge during the warranty period. Ask about their response time and whether callbacks are free during the labor warranty.