Choosing the right HVAC company for a major repair or system replacement is one of the most important decisions a homeowner makes. These 10 questions help you evaluate contractors — and spot the red flags.
A new HVAC system is a significant investment — typically one of the larger purchases a homeowner makes for their property. Choosing the right contractor matters as much as choosing the right equipment. The questions below help you evaluate any HVAC company before committing, and they're equally useful whether you're getting bids on a full system replacement or hiring someone for a major repair.
1. Are You Licensed and Insured in Tennessee?
In Tennessee, HVAC contractors are required to hold a valid state contractor's license for mechanical work. Ask specifically whether the company is licensed for HVAC mechanical work in Tennessee and whether they carry general liability insurance and workers' compensation coverage. A reputable company will confirm this without hesitation and should be able to provide their license number.
Red flag: Hesitation, vague answers, or a company that offers a significantly lower price but can't verify licensure and insurance.
2. How Do You Determine What Size System My Home Needs?
Correct equipment sizing requires a heating and cooling load calculation — Manual J — based on your home's specific characteristics. Ask the contractor how they plan to size the equipment. The answer should involve your home's square footage, insulation, windows, ceiling height, and local climate data — not just matching the tonnage of whatever is currently installed.
Red flag: "We'll just put in the same size you have" or sizing based on square footage alone without any calculation methodology.
3. Will You Evaluate My Existing Ductwork?
New equipment connected to old, leaky, or undersized ductwork will underperform. A quality contractor evaluates the duct system as part of the replacement process and recommends any necessary modifications before installation. Ask specifically whether the duct system will be inspected and what they look for.
Red flag: A contractor who gives a quote without looking at the ductwork at all, or dismisses ductwork evaluation as unnecessary.
4. Can I Get a Written, Itemized Estimate?
A written estimate should clearly identify the equipment model numbers being proposed, the scope of work being performed, any ductwork modifications included, the price for equipment and labor separately, and any exclusions. This allows you to compare proposals from multiple contractors on equal footing.
Red flag: Verbal-only quotes, a written quote that only lists a total price with no breakdown, or pressure to decide before receiving anything in writing.
5. What Warranties Come With the Installation?
There are two separate warranties to ask about: the manufacturer's equipment warranty (covering parts) and the contractor's labor warranty (covering the installation itself). Ask the specific terms of both — how long, what's covered, and what voids coverage. Equipment warranties often require registration within 60 days of installation and documented annual maintenance to remain valid.
Red flag: No labor warranty offered, very short labor warranty periods, or a contractor who doesn't mention equipment registration as part of their installation process.
6. Who Actually Does the Work?
Some HVAC companies subcontract installation work to third parties, particularly during busy seasons. The technicians who show up may not be employees of the company you hired. Ask whether the installation crew are company employees or subcontractors, and whether the work will be supervised by a licensed technician.
Red flag: Vague answers about who performs the work, or installers who arrive without any connection to the company that sold you the job.
7. Will a Permit Be Pulled for This Work?
In many Tennessee jurisdictions, HVAC replacement work requires a permit and inspection. Ask whether a permit is required for your job and whether the contractor will pull one. Unpermitted work can create problems when you sell your home and may affect insurance claims. A reputable contractor will be straightforward about permit requirements for your location.
Red flag: A contractor who says permits aren't necessary when they actually are, or who suggests skipping the permit to save money or time.
8. How Do You Verify the System Is Working Correctly After Installation?
A proper commissioning process — confirming airflow, measuring operating temperatures, verifying refrigerant performance under load, and testing all controls and safety switches — should happen before the technician leaves. Ask specifically what startup and commissioning steps are included.
Red flag: No mention of commissioning beyond a basic operational test, or a crew that installs equipment and leaves without going through a documented startup checklist.
9. Do You Offer Ongoing Maintenance?
The contractor who installs your system is well-positioned to maintain it — they know the equipment, the installation specifics, and the history of the job. Ask whether the company offers annual maintenance plans and what those plans include. Ongoing maintenance from the installing contractor also creates accountability: if the installation was done correctly, they should be comfortable standing behind the work year after year.
10. What Happens If Something Goes Wrong After Installation?
Even a well-done installation can have an issue come up in the first weeks or months. Ask about the process for post-installation concerns: how quickly do they respond, what's covered under the labor warranty, and who you should call. A company that explains this clearly — rather than redirecting you to the manufacturer — is one that stands behind its work.
Use the Answers to Compare, Not Just the Price
The lowest bid isn't always the best value when the contractor who submitted it skipped the load calculation, doesn't pull permits, has no labor warranty, and isn't sure who will actually install the equipment. Use these questions to compare contractors on the quality of the work you're actually buying — not just the number at the bottom of the page.
At Cervino Heating & Air, we're happy to answer all of these questions and welcome homeowners who ask them. Contact us to discuss a replacement or major repair for your Nashville or Middle Tennessee home.
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