Under the Magnuson-Moss Warranty Act, a manufacturer generally cannot void your warranty just because you used a third-party part. The key issue is whether that part actually caused the failure or damage being claimed under warranty.
What the law protects
The law is meant to stop “tying” rules that force you to use only one brand of part or service to keep warranty coverage. In plain language, a company usually cannot say, “Your warranty is void because you used an aftermarket part,” unless it can show that the part caused the problem.
What a manufacturer can deny
A manufacturer may deny coverage for the specific damage if the third-party part was defective, installed incorrectly, or directly caused the failure. So the warranty is not automatically erased for the entire appliance; the denial should be tied to the actual issue.
What this means for washers
For a washing machine, this usually means you can use a compatible third-party motor, pump, belt, or control part without automatically losing warranty protection. But if that part causes electrical damage, leaks, or another failure, the manufacturer can refuse to cover the related repair.
Good practice
Keep receipts and installation records.
Use reputable parts and qualified installation.
Save the original failed part if possible.
Ask the manufacturer or seller for the warranty terms in writing.
If a claim is denied, request written proof showing how the part caused the failure.
The practical rule is simple: third-party parts are not automatically a warranty killer, but they do shift the burden onto the question of cause. If the part did not cause the failure, your warranty rights are generally still there.
Can manufacturers require OEM parts for routine maintenance services
Manufacturers can often prefer OEM parts in their own service programs, but they usually cannot make that a blanket requirement for routine maintenance unless the warranty terms, contract terms, or local law clearly allow it. Under Magnuson-Moss, a warranty generally cannot be conditioned on using only OEM parts unless the manufacturer provides those parts for free or can legally justify the restriction.
What this means
For normal maintenance, a manufacturer may recommend OEM parts because they fit and perform as intended, and OEM-backed service plans often bundle those parts into the service. But “recommend” is different from “require.”
If a company says the warranty stays valid only if you use its parts, that can become a prohibited tying arrangement unless it meets the law’s exceptions. The practical test is whether the manufacturer is trying to force a purchase of its branded parts just to keep coverage.
When OEM can be required
OEM parts may be required when:
The service contract specifically says so.
The part is covered by a factory-backed maintenance plan.
Safety, compliance, or performance rules make the OEM specification necessary.
The manufacturer can show that a non-OEM part caused the failure.
When OEM cannot be imposed
A manufacturer generally cannot tell you that routine maintenance voids the warranty just because you used a compatible third-party filter, belt, gasket, or similar part. If the part did not cause the failure, warranty protection for unrelated problems is usually still there.
Practical rule
If you are under warranty, the safest approach is to read the maintenance terms carefully and keep records of every service and part used. If the machine is outside warranty, you usually have more freedom to choose OEM or quality aftermarket parts based on cost and availability.
So the short answer is: manufacturers can recommend or contract for OEM parts in some maintenance programs, but they generally cannot force that requirement across the board for routine maintenance without a legal or contractual basis.