The 10 questions to ask every HVAC contractor before signing. Licensing verification, permit process, warranty terms, and how to compare quotes properly.
Choosing an HVAC contractor is a more consequential decision than choosing the equipment. A well-installed mid-tier system outperforms a poorly installed premium system every time. These 10 questions give you a reliable framework for evaluating contractors before you commit.
HVAC contractor licensing requirements vary by state. Most states require a specific HVAC/mechanical contractor license separate from a general contractor license. Verify the license number on your state's contractor licensing board website before signing. Unlicensed work voids manufacturer warranties and may affect your homeowner's insurance.
The contractor should pull the mechanical permit, not the homeowner. If a contractor asks you to pull the permit, that's a red flag — it typically means they don't want to be on record with the licensing authority. Permit fees should be passed through at cost and itemized in the quote.
The permit requires a final inspection before the project is closed. Confirm that the inspection is included in the contract and that the contractor is responsible for scheduling it. Uninspected work creates liability at resale.
Equipment manufacturers typically warrant parts for 5–10 years (with registration). Labor warranties are the contractor's responsibility and are typically 1 year. Get the labor warranty in writing — verbal commitments are unenforceable. Confirm whether the warranty is with the contractor directly or transferred to a third party.
Ask every contractor to quote the same SEER rating. Comparing a 14-SEER quote against a 18-SEER quote is not an apples-to-apples comparison. Use the estimator below to understand the efficiency tradeoff before your contractor conversations. See also: what affects HVAC cost.
Duct leakage reduces delivered system efficiency by 20–30%, per U.S. Department of Energy research. A contractor who quotes a new system without inspecting the existing ductwork is not giving you a complete picture. Ask whether duct inspection and sealing are included, and if not, what they cost separately.
Many HVAC companies subcontract installation work. This isn't inherently a problem, but you should know who will be in your home and whether the subcontractors carry their own insurance. Ask whether the installing technician is certified (NATE certification is the industry standard for HVAC technicians).
Proper HVAC sizing requires a Manual J load calculation — a engineering assessment of your home's heating and cooling requirements based on insulation, windows, orientation, and occupancy. Most building codes require it for new installations. A contractor who sizes by square footage rule-of-thumb rather than Manual J is likely to oversize the system, which causes short-cycling, poor dehumidification, and premature wear.
For replacements, the old refrigerant must be recovered (not vented) per EPA regulations. Recovery is typically included in the installation price, but confirm. For R-22 systems, disposal fees may be higher. For new systems, confirm that refrigerant charging is included and that the system will be charged to manufacturer specifications before the technician leaves.
Recent references (not 3-year-old testimonials) tell you about current quality and reliability. Ask for at least two recent installation references and follow up with them. Ask specifically about whether the project came in on time, whether the permit inspection passed, and whether any issues arose after installation. Use the estimator to build a planning range before your contractor conversations. See also: replacement cost ranges and repair vs replace decision framework.