Product Warranty Rights: What the Law Covers

This guide is general information, not legal advice. Laws vary by state and city — check your local rules or speak to a licensed attorney for your situation.

A dishwasher that stops draining at month eleven. A smart thermostat whose screen goes dark a week after the return window closed. A robot vacuum where the manufacturer says the warranty is void because you used a third-party filter. These are the moments when most people discover they do not really know what a warranty promises — or what the law promises on top of it.

US warranty law is more protective than the fine print suggests, but it has real limits. The federal framework is the Magnuson-Moss Warranty Act, enforced by the Federal Trade Commission, sitting on top of state laws that create “implied” warranties. Here is how the pieces fit, written for readers of HomePlusDeals.Com who buy appliances and connected gadgets and want to know where they stand when one fails.

The Magnuson-Moss Warranty Act in brief

The Magnuson-Moss Warranty Act (15 U.S.C. §§ 2301–2312) governs written warranties on consumer products. According to the FTC’s Businessperson’s Guide to Federal Warranty Law, the core points are:

• Nobody has to offer a written warranty. The Act does not require one. It regulates warranties that companies choose to give.
• Written warranties must be clearly disclosed. For products costing more than $15, the terms must be set out in a single, easy-to-read document and made available before you buy — in the store or, since the 2015 E-Warranty Act changes, online under certain conditions.
• Warranties on products over $10 must be labelled “full” or “limited.”
• Implied warranties cannot be wiped out. A company that offers a written warranty, or sells a service contract within 90 days of the sale, cannot disclaim the implied warranties that state law provides.
• Tie-in conditions are generally banned. More on that below, because it matters a great deal for smart products.

Full vs limited warranty

The words “full” and “limited” are legal labels, not marketing adjectives.

Most appliances and electronics carry limited warranties. That is legal, but it means you should read exactly what is covered: parts only or parts and labor, whether you pay to ship the item, and whether only the first owner can claim. A product can also be part full and part limited — for example, a full warranty on a compressor and a limited one on everything else.

Implied warranties: the promises nobody wrote down

Even with no written warranty, state law usually gives you two unspoken guarantees. The FTC’s consumer guide to warranties describes them:

• Implied warranty of merchantability — the product will do what it is supposed to do. A refrigerator must keep food cold; a smart lock must lock.
• Implied warranty of fitness for a particular purpose — if the seller recommended a product for a specific use and you relied on that advice, it must be suitable for that use.

These apply unless the product is sold “as is” or with a written “no warranty” notice, where state law allows that. The FTC notes some implied warranties last up to four years in some states, and some states do not allow “as is” sales of consumer goods at all.

Why this matters: when a written limited warranty runs out, an implied warranty may still be running. A limited warranty can cut the implied warranty’s duration down to match its own, but a company that offered a written warranty cannot eliminate it entirely.

”Warranty void if removed” stickers and third-party parts

This is where federal law most directly protects people who maintain their own devices.

Under Magnuson-Moss, a warrantor generally cannot make coverage conditional on using a particular brand of parts or service — unless it provides those parts or that service free, or has obtained a waiver from the FTC. A company can still deny coverage for damage that unauthorized parts or repair actually caused. But it cannot void your warranty simply because a non-branded filter or an independent repair shop was involved.

The FTC has acted on this repeatedly. In July 2024 it warned companies to stop warranty practices that harm consumers’ right to repair, sending letters to three computer hardware makers over “warranty void if removed” stickers placed where they hinder routine maintenance and repairs, and to five companies — including several air purifier brands — over statements that consumers had to use specified parts or service to keep their warranty.

What this means in practice for home tech:

• Air purifier, vacuum and water filters: using a compatible third-party filter is generally not grounds to void the warranty. If the filter damages the unit, that damage can be excluded.
• Appliances: an independent technician’s repair does not automatically void coverage on unrelated parts.
• Electronics: opening a device to replace a battery or clean a fan should not, by itself, void the warranty, though damage you cause in the process may not be covered.

If a company tells you a warranty is void because you used a third-party part or repair shop, the FTC asks consumers to report it at ReportFraud.ftc.gov.

Extended warranties and service contracts

That “protection plan” at checkout is not a warranty in the legal sense. It is a service contract — an optional, separately priced agreement. The FTC’s article on extended warranties and service contracts makes several practical points:

• It is not good value if it does not cover more than the warranty already included with the product.
• It is only as good as the company responsible for honouring it, which is often not the manufacturer or the store.
• If something is not listed in the contract, assume it is not covered.
• Ask about deductibles, shipping costs, reimbursement caps and whether missed maintenance can void a claim.
• Setting money aside in savings can be a better alternative for some buyers.

Before buying one, check the length of the manufacturer’s warranty, whether your credit card offers any purchase or warranty-extension benefit (terms vary by issuer), and what the cancellation and refund terms are. For a smart device, also ask how a claim works if the problem is software rather than hardware.

Returns vs warranty: two different rights

People often blur these, and it costs them.

The practical rule: if a new device is defective inside the return window, use the return. It is almost always faster than a warranty claim. Smart home gear deserves particular care here — test compatibility with your existing system and Wi-Fi in the first week. For thermostats, our smart thermostat buying guide covers the wiring checks that catch most “it doesn’t work with my system” problems while you can still return it.

How to make a warranty claim — and complain if it fails

The FTC’s warranty guidance suggests this order:

1. Read the warranty and gather your receipt, model and serial numbers.
2. Contact the seller first, then the manufacturer through the claim process in the warranty.
3. Put it in writing if the first contact fails. The FTC suggests writing to the manufacturer at the address in the warranty, by certified mail with a return receipt. Keep copies.
4. Report defects before the warranty expires. The FTC notes that if you reported a defect during the warranty period and it was not properly fixed, the company must correct it, even after the warranty runs out.
5. Use the dispute program if the warranty names one; some require it before you can sue.
6. Escalate. Report problems to the FTC at ReportFraud.ftc.gov and to your state consumer protection office or attorney general. Magnuson-Moss also gives consumers a right to sue for breach of warranty, and small claims court is often a practical option for appliance-sized disputes.

Quick checklist

• Check whether the warranty is full or limited, and what it covers.
• Keep receipts, model and serial numbers, and a copy of the warranty.
• Register the product if useful — but a full warranty cannot require it.
• Use the store return window for early defects.
• Third-party filters and independent repairs generally do not void coverage on their own.
• Report defects in writing before the warranty ends.
• Treat extended warranties as optional service contracts and read the terms.
• Escalate to the FTC and your state consumer office if a company will not honour its obligations.

Related guides

If a failed appliance caused damage — a leaking washer or a dishwasher flood — your homeowners policy may be involved; see our homeowners insurance claim guide. Renters with a broken landlord-supplied appliance should start with renters’ rights for repairs, and anyone hard-wiring a new appliance should check do you need a building permit?. All our legal guides on HomePlusDeals.Com take the same practical approach.