How to Choose an HVAC Contractor: 8 Questions to Ask Before Signing Anything

Here's an uncomfortable truth: a $4,000 system installed by an excellent contractor will outperform a $7,000 system installed by a mediocre one. Installation quality determines 80% of your system's real-world efficiency, comfort, and lifespan. The equipment brand matters - but the contractor matters more.

Question 1: Are You Licensed, Bonded, and Insured?

This is non-negotiable. Every HVAC contractor should hold a valid state/local contractor's license, carry general liability insurance ($1 million minimum), carry workers' compensation insurance, and be bonded. Ask for proof of all four. If a contractor can't or won't provide documentation, walk away. Unlicensed work voids equipment warranties, creates code violations that affect home sales, and leaves you liable if a worker is injured on your property.

Question 2: Will You Perform a Manual J Load Calculation?

A Manual J calculation is the engineering foundation for proper system sizing. Any contractor who skips it and sizes based on square footage alone ("you've got 2,000 square feet, you need a 4-ton unit") is taking a shortcut that compromises your comfort and efficiency. A proper Manual J takes 1-2 hours and considers every variable that affects heating and cooling load. If the contractor can't explain what a Manual J is or says it's not necessary, find a different contractor.

Question 3: What Specifically Is Included in Your Quote?

A detailed written quote should include specific equipment model numbers (not just brand and tonnage), all materials and parts, labor for the complete installation, any ductwork modification or repair, thermostat, permit fees, disposal of old equipment, startup and commissioning, and warranty registration. Beware of vague quotes that say "Carrier 3-ton system installed - $6,500" without specifying the exact model, efficiency rating, or what's included. Those quotes inevitably lead to change orders and surprise costs.

Question 4: What Is Your Warranty - Equipment AND Labor?

Equipment warranties are provided by the manufacturer (typically 10 years on parts). But labor warranties come from the contractor - and they vary dramatically. Ask specifically how long the labor warranty covers repairs after installation, whether the warranty is transferable if you sell the home, what the contractor's process is for warranty claims, and whether the contractor will be around in 5-10 years (check how long they've been in business). A 1-year labor warranty is the minimum. Better contractors offer 2-5 year labor warranties. The best offer 10-year parts AND labor through manufacturer programs.

Question 5: Can You Provide 3-5 References from Recent Installations?

Ask for references from installations completed in the last 6 months - not from 5 years ago. Contact at least 2-3 references and ask whether the project was completed on time and on budget, how the crew treated their home during installation, whether any issues arose and how they were resolved, and whether they're satisfied with system performance months later. Also check online reviews - but focus on review patterns, not individual reviews. A company with 200 reviews averaging 4.5 stars is more reliable than one with 15 reviews averaging 5.0 stars.

Question 6: Who Will Actually Do the Installation?

Some contractors use subcontractors or temporary labor for installations. Ask whether the installation will be done by the company's own employees, how many installers will be on the crew, what certifications the installers hold (NATE certification is the gold standard), and who the project lead is and how to reach them. Having the company's own NATE-certified technicians do the work is ideal. Subcontracted labor isn't necessarily bad, but you should know who's working in your home.

Question 7: What Does the Installation Process Look Like?

A quality contractor should be able to walk you through the timeline: day-of-installation procedures, how they'll protect your home (drop cloths, shoe covers, cleanup), inspection and permit process, system commissioning and testing, thermostat setup and homeowner walkthrough, and post-installation follow-up. The entire process for a standard replacement should take 1 day for a straight swap, 1-2 days if ductwork modification is needed, and 2-3 days for complex installations or full system redesigns.

Question 8: What Financing Options Do You Offer?

Most reputable contractors offer financing through manufacturer programs or third-party lenders. Common options include 0% APR for 12-60 months (promotional manufacturer financing), low-APR loans through GreenSky, Service Finance, or similar lenders, same-as-cash financing (0% if paid within the promotional period), and home equity financing for larger projects. Financing shouldn't pressure you into a more expensive system, but it can make a higher-efficiency system affordable by spreading the cost over time - and the energy savings partially offset the monthly payment.