Before you sign an HVAC replacement contract, ask about load calculations, permits, EPA certification, and warranty terms. Here is what good answers sound like.
Licensing, permit, lien and tax rules vary by state and city and change over time. This guide is general information, not legal or tax advice; check with your local building department, state licensing board or a professional for your situation.
Checklist
- A Manual J load calculation, which takes an experienced technician about 15 minutes for most homes, should come before any equipment quote.
- EPA Section 608 certification is required for technicians handling refrigerant; Universal covers all equipment types and the credential does not expire.
- An oversized air conditioner short cycles and fails to remove humidity, leaving rooms uncomfortable even when the thermostat reads correctly.
- The contractor should pull the permit, and warranty coverage for parts and labor should be written into the contract.
- Old refrigerant must be recovered with certified equipment, so make sure removal and disposal of the old unit are in the quote.
A new furnace or air conditioner is one of the bigger checks you will write as a homeowner, and the installation matters as much as the equipment. Contractors vary widely in how they size systems, handle permits, and stand behind their work. These seven questions separate careful installers from equipment sellers. Ask every one of them before you sign.
1. Will You Do a Load Calculation Before Quoting Equipment?
A legitimate replacement starts with a Manual J load calculation, the standard from the Air Conditioning Contractors of America (ACCA) for measuring how much heat a home gains in summer and loses in winter. The technician should take real measurements: square footage, window sizes and types, insulation levels, ceiling heights, and how many people live in the house. For most homes, an experienced technician needs about 15 minutes, a walk around the house with a tape measure and a look in the attic.
If a contractor prices the job based only on the size of your old unit, press hard. Copying the old system’s capacity repeats any mistake the original installer made. The ACCA Quality Installation standard allows skipping the calculation only when a load calculation already exists and neither the house nor the duct system has changed. Ask to see the numbers the calculation produced, not just a summary.
2. What Equipment Size and Efficiency Rating Do You Recommend, and Why?
Manual J produces the load; it does not pick the equipment. Equipment selection comes from Manual S, which matches manufacturer performance data to the calculated heating and cooling loads, including both temperature and humidity. Ask the contractor to explain which numbers led to the recommended size and why that efficiency level makes sense for your home and climate.
Size matters more than most homeowners realize. An air conditioner that is too large cools the house quickly and then shuts off, a pattern called short cycling. Those short runs do not remove enough humidity, so the house can feel damp and uncomfortable even while the thermostat reads the right temperature. Equipment that is the wrong size or starved for airflow can also show up as repeated failures of parts like capacitors and compressors. An answer of “bigger is safer,” with no reference to your load numbers, means the contractor is guessing.
Red flags
Never accept a same-size swap without a load calculation. If the original system was never sized correctly, the replacement inherits the mistake, and the same comfort problems return with the new equipment.
3. Who Pulls the Permit, and What Inspections Are Included?
Permit rules for replacing HVAC equipment vary by location, so check with your local building department before work starts. The contractor should pull the permit in the company’s name and schedule the inspections. The question of whether a job needs one is covered in do you need a building permit?.
Treat suggestions to skip the permit to save time or money as a red flag, and be cautious if a contractor asks you to pull it as the homeowner. An unpermitted installation means no inspector ever checked the work, which can complicate a future sale.
4. Are Your Technicians Licensed and EPA-Certified for Refrigerant?
Two credentials matter here. First, check what licensing applies to HVAC contractors where you live; rules vary by state, so verify the license yourself using the steps in how to check a contractor’s license.
Second, federal law covers anyone who touches refrigerant. Section 608 of the Clean Air Act makes certification mandatory for technicians whose work on refrigerant equipment, whether maintaining it, servicing it, repairing it, or disposing of it, could let refrigerant escape into the air. Technicians earn the credential by passing a certification test. The certification comes in four types, and Universal certification covers every equipment category; Type II is the one typically required for mainstream air conditioning work. These credentials do not expire, and apprentices are exempt only while closely and continually supervised by a certified technician.
The same federal rules prohibit intentionally venting refrigerant and require certified recovery equipment when refrigerant is removed from a system. Working without certification can bring fines of up to $45,000 per day. Ask which certified technician will actually be on your job, and get the name.
5. What Exactly Does the Warranty Cover, Parts or Labor?
Expect two warranties on a replacement: the manufacturer’s warranty on equipment and the contractor’s warranty on workmanship. They are not the same thing. Ask how long each lasts, what is excluded, and who pays labor on a failed part, since parts coverage alone can still leave you with a service bill. Ask what could void the coverage and whether the equipment must be registered to activate the full term.
Put every warranty promise in the written contract. The items in what a home improvement contract should say apply to an HVAC replacement just as they do to a remodel.
6. What Are the Payment Terms, and How Will the Old Equipment Go?
A common structure ties payments to progress: a modest deposit, a payment when equipment is set, and the balance only after startup and inspection. Treat a demand for most of the money upfront as a red flag, and be wary of pressure to sign financing before the scope is settled. Confirm what insurance the company carries; the coverage described in what insurance your contractor should carry is the baseline to expect.
Ask whether removal and disposal of the old unit are included in the quote. The refrigerant inside it must be recovered with certified recovery equipment rather than released, and hauling away the old system is part of doing the job properly. If subcontractors are involved, ask for lien waivers with each payment so you are not exposed if someone down the chain goes unpaid.
7. How Do You Handle Ductwork, Thermostats, and Code Requirements?
New equipment cannot fix bad ducts. Leaky, under-insulated, or undersized ductwork is a common reason systems underperform even after a full replacement. Ask whether the contractor will inspect the duct system, seal leaks, and verify airflow at startup, and whether the duct design follows Manual D, the ACCA standard for residential duct systems. Contractors who test and commission their installations are checking their own work before you discover the problems.
Ask what happens to the thermostat, whether your existing control works with the new equipment or an upgrade is included in the price. Finally, ask which code requirements apply, such as equipment clearances, electrical connections, and condensate drainage. These vary by locality, and the permit inspector will check them.
Keep reading
- HVAC myths that cost you money: More popular advice that raises bills or shortens equipment life.
- When a contractor job goes wrong: Steps to take if the installation turns into a dispute.
- How to hire a contractor without regrets: The screening process to run before you collect any estimates.
Homeowners ask
Do I really need a load calculation if I am just replacing my old system?
Yes, unless a valid calculation already exists and neither the home nor the duct system has changed. Copying the old unit’s size repeats any sizing mistake the original installer made.
What certification should an HVAC technician have to handle refrigerant?
EPA Section 608 certification, which technicians earn by passing a certification test. Type II covers mainstream air conditioning work, and Universal certification covers all equipment categories.
Who should pull the permit for an HVAC replacement?
The contractor, in the company’s name. Requirements vary by state and city, so confirm with your local building department, and be wary of anyone who asks you to pull the permit yourself.
What payment schedule is reasonable for an HVAC installation?
Payments tied to progress, with the balance due after startup and inspection. A demand for most of the money upfront is a red flag.