A warranty is a promise you price today against a cost you may pay later. On HVAC work that promise is harder to reason about than in most trades, because three separate warranties ride on the same install and the customer hears all three as the single word you said at the door. The parts came from a manufacturer with its own multi-year coverage. Your labor came from you, with whatever term you set. And somewhere between them sits the labor to act on a parts claim, which neither the maker nor your workmanship warranty may cover. Set your labor term without thinking through those seams and you will either give away return visits you should have billed, or promise a homeowner something the manufacturer never agreed to.
The short answer: how long an HVAC labor warranty should be
For most residential HVAC work, a one-year labor warranty on the install is the term a customer expects and one you can stand behind. It covers your work, the connections you made, the unit you set, the ductwork you tied in, for a full cooling and heating season, which is long enough to surface an installation fault and short enough that you are not on the hook for wear or abuse two years on. On a major system replacement, a full furnace and coil and condenser changeout, a two-year labor term is common and reads as confidence rather than exposure, because a properly commissioned system either holds from the start or fails early.
Ninety days exists in the trade, and there are honest uses for it, but understand what a blanket ninety-day labor policy signals to a homeowner comparing quotes. Against a competitor offering a year on labor, ninety days reads as a contractor who does not expect the work to last, and it costs you the sale on price-neutral bids. The move is not a single term stamped on everything. It is a default of one year on standard installs and service, two on major changeouts, and a deliberately shorter term only where you are genuinely warranting your labor on top of equipment or conditions you cannot vouch for, an add-on to an aging system, say, where the rest of the equipment is out of your control.
The three warranties on every HVAC install
The word "warranty" on an HVAC job hides three different promises, and nearly every dispute lives in the gaps between them. The first is the manufacturer's parts warranty. When you install a new condenser or furnace, the maker warrants the physical components, compressor, coil, heat exchanger, control board, against defect for a set number of years, and coverage is for the replacement part itself.1 Labor to install the replacement is industry-wide a separate matter that the manufacturer does not pay for.
The second is your labor warranty, sometimes called the workmanship warranty. It covers the quality of what you did: whether the lineset was brazed clean, the system charged to spec, the condensate routed correctly, the electrical landed right. If the system fails because of how you installed it, that is yours to fix, labor included, for whatever term you set. The third promise is the one almost nobody names out loud, and it is where the money leaks: the labor to act on a manufacturer's parts claim. When a warrantied compressor fails in year five, the part is free from the maker, but recovering the refrigerant, pulling the old compressor, brazing in the new one, and recharging the system is hours of skilled labor that the manufacturer's parts warranty does not touch and your one-year labor warranty already expired on.
Operators get into trouble when they let the homeowner collapse all three into "it's under warranty for ten years." The customer hears one promise. You made one of the three, the manufacturer made another, and the third belongs to whoever the paperwork says it belongs to. Name them separately when you quote and the year-five compressor call becomes a manufacturer's parts claim with your labor billed, instead of a fight about what "warranty" meant.
The registration trap that turns a ten-year warranty into five
Here is the detail that burns HVAC contractors more than any other, because it fails silently and surfaces years later with your name on it. Most major manufacturers offer their headline parts warranty, commonly ten years, only if the equipment is registered online within a short window after installation, typically sixty days. Register in time and the homeowner gets the ten-year parts term. Miss the window and the same unit falls back to the base warranty, which for several brands is five years.12
Nobody feels this on install day. The system runs, the customer is happy, the paperwork gets filed. Then a coil fails in year seven. The homeowner calls the manufacturer expecting the ten-year coverage they believe they have, and learns the unit was never registered, so it dropped to five years and the coverage ran out two years ago. Now they are paying full price for a part they thought was free, and they remember exactly who installed it. Whether or not registration was legally your job, in the customer's mind the contractor who put it in is the one who cost them a covered part. That is a review and a lost referral over a form that takes five minutes to submit.
Who registers the equipment, you or the customer?
The registration window forces a decision most shops never make deliberately: is submitting the manufacturer registration your job or the homeowner's? Manufacturers often allow either party to do it, which is exactly why it falls through the cracks, because "either could" quietly becomes "neither did." Leaving it to the customer is the cheap choice on paper and the expensive one in practice. A homeowner who just spent thousands on a system does not know the sixty-day clock exists, will not read the fine print, and will blame you when the shortfall appears.
The defensible policy is to own the registration yourself and make it a fixed step in closing out every install, the same as pulling the permit or hauling the old unit. It protects the customer's coverage, it protects your name, and it costs a few minutes per job. If you do choose to leave it to the homeowner, then owning it means telling them so in writing: that the equipment must be registered within the manufacturer's window to keep the full parts term, that it is their responsibility, and here is the link. Handing it off silently is the one option that reliably ends in a year-seven phone call you cannot win. Either you do it, or you document that they must. Not deciding is deciding to eat the goodwill later.
When a callback is free, and when it is a billable job
This is the decision the whole warranty exists to make, and most operators make it in the moment, standing in the customer's mechanical room under pressure, which is exactly when work gets given away. Sort every callback into one of three buckets before you drive out. First, workmanship failure: the system fails because of how you installed it, a leaking flare you made, a loose connection, a condensate line that was never pitched right. That is your labor warranty, and inside the term it is free, full stop. Do not nickel-and-dime it; the goodwill of a fast no-charge fix on your own error is worth more than the hour.
Second, a warrantied part that fails on its own: a compressor, a board, a coil that dies from a manufacturing defect rather than your install. Here the split matters most. The part is the manufacturer's to replace, but the labor to swap it is a real job, and if your labor term has expired, that labor is billable even though the part is free. On a refrigerant-circuit repair there is a further wrinkle: recovering and recharging refrigerant is work only a certified technician may legally perform under the Clean Air Act, and it carries real cost in time and materials.3 A homeowner who heard "ten-year warranty" expects the whole compressor swap for nothing and is startled by a labor bill. That conversation is survivable only if you separated the part from the labor back when you quoted the job. Third, wear, abuse, or neglect: a clogged filter that burned out a blower, a system nobody ever maintained, storm damage. Billable, and worth explaining kindly so it does not read as you dodging your own work.
The reason the sort has to happen before you arrive is that once you are on site, the pressure runs one direction. It is easier to swallow the charge than to have the conversation, so the undocumented callback drifts toward free by default. If the bucket was already decided by what you wrote when you did the original job, you are not negotiating in the hallway. You are reading back terms the customer already approved.
Should you sell an extended labor warranty?
Because the manufacturer never covers labor, a gap sits open for years: the homeowner has a decade of parts coverage and, after your term ends, no coverage at all on the labor to install those parts. Extended labor warranties exist to fill it, and they come in two forms. You can offer your own, pricing a longer labor term into the job and self-insuring the risk, or you can sell a third-party labor warranty backed by an outside administrator, where the homeowner pays a premium and the administrator reimburses the labor on a covered failure.
Selling one is a legitimate revenue line, but price it as insurance, not as a giveaway. If you extend your own labor coverage to five or ten years, you are betting your install quality against the loaded cost of every return visit over that span, and that reserve has to live in the price. Do not stretch a free labor warranty to a decade to win a bid; you will fund every future callback out of a margin you already spent. Whether you offer it or not, the customer-facing point is the same. The homeowner should leave understanding that the manufacturer covers parts, you cover labor for your stated term, and coverage on labor beyond that term exists only if they bought it. Silence on that third layer is what manufactures the year-five surprise.
Put the warranty terms on the quote and the invoice
Every problem above is the same problem: the customer and the contractor remember the warranty differently, and there is nothing in writing to settle it. The fix is to stop treating the warranty as something you say and start treating it as lines on the document. When you quote a system replacement, the quote should state your labor term in plain words, note that the equipment carries the manufacturer's separate parts warranty for a stated number of years, note that the full parts term depends on registration within the manufacturer's window and say who is doing it, and note that labor to act on a parts claim after your term is billed. That is four short sentences. It converts every future callback from a memory contest into a look at paperwork the customer already signed.
The same terms belong on the invoice when the job closes, because the invoice is the document the homeowner keeps and digs out when something fails later. An invoice that reads "new system installed, $8,400" tells a year-five caller nothing and invites the free-swap expectation. An invoice that lists the equipment by model, the labor, your warranty term, the manufacturer's parts term, and the registration status settles the year-five call before it starts. This is the same discipline that makes a bill fast to pay in the first place, covered in the guide on the HVAC invoice, and it pairs with a fair, stated service call fee so a billable return visit already has a number the customer understands. The warranty is not a slogan on your truck. It is a set of terms on the page the customer signed.
A worked example: a system install and two callbacks
The numbers below are illustrative, chosen to show how the boundaries behave. Use your own costs and your own market's terms.
You install a new air conditioner and coil for $8,400: roughly $5,600 in equipment and $2,800 in labor, plus permit and materials. On the quote and the invoice you state a one-year labor warranty on the install, note that the equipment carries the manufacturer's parts warranty, ten years if registered within sixty days and five if not, and note that you will submit the registration as part of closeout. You have priced a small callback allowance into that $2,800, and you register the unit the day it is commissioned.
Month four, the customer calls: the system is short-cycling and there is water at the air handler. You find the condensate trap you set was never primed and the drain is backing up. That is workmanship, squarely inside your term. You drive out and fix it at no charge, and it costs you an hour of time you already reserved for in the labor price. The customer tells a neighbor you stood behind the work. That callback was never meant to make money. It was meant to be already paid for, and it was.
Year five, the same customer calls: the compressor is dead, defective per the manufacturer. Because you registered the unit, it is inside the ten-year parts warranty, so the maker ships a replacement compressor at no charge for the part. But your one-year labor term ended four years ago, and the manufacturer never covered labor at all. Recovering the refrigerant, swapping the compressor, and recharging the system is most of a day for a certified tech, and it is billable. Because your invoice from five years ago spelled out that the part and the labor are two different things, the customer reads it back and understands the compressor is free but the labor is not. Had you also let the registration slide, the story would be worse: the part would be out of warranty at year five and the homeowner would be paying for both, blaming you for the form nobody submitted. The labor term did not decide these outcomes. The lines on the quote and the registration you filed did.
Put the warranty term on the quote, not in your memory
We built EosLog's quote generator so an HVAC contractor can state the labor term, the manufacturer's separate parts coverage, and who registers the equipment on the same page the customer approves, then carry it onto the invoice. When a callback comes, you read back the terms instead of negotiating them.
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No account required. You can also create a free EosLog account to save your warranty wording and reuse it on every quote, or see the plans first.
Sources and further reading
- Manufacturer residential HVAC warranty terms vary by brand and model; parts coverage commonly runs several years and reaches its full term only with timely online registration, while manufacturers do not cover installation labor. See a manufacturer's published warranty page, for example Goodman's air conditioner limited-warranty explainer (ten-year parts warranty with online registration within sixty days of installation; otherwise a five-year term), and confirm the exact terms of the equipment you install.
- Trane, Warranty and Registration (registered limited warranty extends coverage when the product is registered within sixty days of installation; unregistered units default to the shorter base limited warranty). The register-within-sixty-days pattern is consistent across several major HVAC brands.
- U.S. Environmental Protection Agency, Section 608 Technician Certification Requirements (under the Clean Air Act, technicians who maintain, service, or repair equipment that could release refrigerant must be EPA-certified). Refrigerant-circuit labor is not something an uncertified party can legally perform.
- Federal Trade Commission, A Businessperson's Guide to Federal Warranty Law (Magnuson-Moss Warranty Act; written-warranty rules and the prohibition on tying a manufacturer's warranty to the use of a specific installer or branded part).
- U.S. Bureau of Labor Statistics, Occupational Outlook Handbook, Heating, Air Conditioning, and Refrigeration Mechanics and Installers (median annual wage $59,810 in May 2024; used here as the employee-wage baseline for callback cost, not a billed rate).
This guide reflects general US HVAC practice as of 2026 and is not legal advice. Warranty norms, registration windows, licensing, and refrigerant rules vary by manufacturer and by state, and the figures in the worked example are illustrative. Confirm your own costs, your equipment maker's warranty and registration terms, and your state's rules before setting a warranty policy for your business.