Will homemade laundry soap work in an HE washer, or void the warranty?
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No washer maker whose guidance was read for this page mentions homemade laundry soap at all, and none of their support pages says that using it voids a warranty. What they do say is specific: LG washers "require that you use a HE detergent," Samsung recommends HE detergent because ordinary detergent "will cause excessive amounts of suds," and LG's manual warns that a detergent that "does not dissolve easily" or has "high viscosity" will "leave a residue on the tub." A homemade bar-soap mix is not sold as an HE detergent, and the liquid version is meant to thicken. Below are the makers' words, what they leave open, signs of buildup and how to clean the machine.
What the manufacturers say, word for word
An HE (high-efficiency) washer is a front loader or a high-efficiency top loader that uses much less water than an older machine, which is why suds and residue matter more in it.
| Maker and source | What it says about detergent | What it says about residue or suds |
|---|---|---|
| LG, support page (June 16, 2026) | "LG washers require that you use a HE detergent." HE detergent "is specifically designed for high efficiency machines that use very little water" [1] | "Seeing little or no suds should be considered normal" [1] |
| LG, support page (May 28, 2026) | "If you are not using a HE detergent, it will be necessary to switch immediately" [2] | "Excess suds create residue buildup in the drum over time" [2] |
| LG, WM3997HWA owner's manual | "Only use HE detergents, because using a regular detergent may produce excessive suds." "Use the correct amount of detergent as indicated on the detergent packaging" [3] | "If you use a detergent that does not dissolve easily or a detergent with high viscosity, it will leave a residue on the tub, which may not rinse properly." "Using too much detergent can cause a build-up in the tub" [3] |
| Samsung Australia, support page (Sept 29, 2021) | "Samsung recommends using 'HE' (High Efficiency) detergent." "Non 'HE' detergent normally has high sudsing properties" [4] | A SUDS error "is usually caused by too much detergent, or the wrong type of detergent," and is "not an indication of a malfunction" [4] |
The Samsung page is from Samsung's Australian site. It is included because it is the manufacturer's own wording; check the manual for your model and country.
What the manuals leave open
Four questions have no manufacturer answer in the sources read:
- Whether a soap-based homemade mix counts as HE detergent. The manuals define the requirement by the product sold as HE detergent and by its behavior (low suds, dissolves easily, rinses away). They do not discuss soap.
- The warranty. None of the LG, Samsung, Whirlpool or Maytag pages read discusses warranty coverage and detergent. The warranty document that came with your machine is the only source that can answer this for you; read its exclusions.
- How a homemade mix compares to HE detergent in a test. No manufacturer or extension test was found.
- Hard water. LG's pages address soft water ("Use less detergent for soft water" [3]; soft water "can also cause detergents to over-suds" [2]) but not soap and hard water together.
The reader forums that raise this question, and the columnists who answer it, cite no manufacturer either way. This page does not guess.
How the two UF/IFAS recipes line up against the manuals
The table is an editorial reading of the manuals against the published recipes. No manufacturer has made this comparison.
| Manual concern | Powder (2 tablespoons a load) | Liquid (1/4 cup a load in HE machines) |
|---|---|---|
| Suds | The manuals' suds warnings are written about detergent; soap in hard water reacts with calcium to form scum [8] | Same soap, diluted |
| Dissolving | Chopped soap and powders must dissolve in a short, low-water cycle; cold washes make this harder | Already dissolved, but UF/IFAS lets it "sit overnight to thicken" [5] |
| Viscosity | Not applicable | A thickened liquid is what LG's residue warning describes [3] |
| Dose | Small and measured | UF/IFAS gives a separate HE dose of 1/4 cup [5] |
UF/IFAS does print an HE dose for its liquid [5], which shows the authors expected HE use. It does not say the recipe was tested in an HE machine.
Signs of buildup and what each means
| What you see | What it can mean | What to do |
|---|---|---|
| A gray film or greasy feel inside the drum or on the door seal | Detergent or soap residue building up, which LG ties to excess suds and to detergents that do not dissolve [2][3] | Run the cleaning cycle your manual names (below) and cut the dose |
| A musty smell from the door or drawer | Residue and moisture left in the seal or dispenser | Wipe the seal; Whirlpool says to "Check the door seals often and wipe them down periodically to help prevent residue buildup" [6] |
| A SUDS code or suds at the door glass | Too much product, or the wrong type for the machine [4] | Use less, or switch to an HE detergent |
| Stiff or dingy towels | Soap scum in the fabric from hard water | See hard water and laundry |
| Undissolved flecks on clothes | Powder or soap not dissolving in the cycle | Dissolve the powder in warm water first, or use a warmer cycle if the care labels allow |
Cleaning the machine the way its maker directs
Use the cleaning method in your own manual first. The makers read for this page say:
- LG: perform "a cleaning cycle" to "remove residue buildup from the drum" [2].
- Whirlpool: add "a cleaning product such as an affresh® Washing Machine Cleaner tablet" and select "a normal, hot water cycle"; if you have no tablets, "bleach may also be a possible option, but check your washer use and care guide first" [6]. Affresh is a Whirlpool brand, so read that as the maker naming its own product.
- Maytag: "stick to manufacturer-approved cleaning methods," run "a monthly Clean Washer with affresh® cycle," and note that "bleach should not be used in certain front load models" [7].
- Dispensers: both Whirlpool and Maytag say to remove the drawers and soak them in equal parts white vinegar and water [6][7].
Both also say to keep vinegar out of the drum. Maytag: "Avoid using vinegar in the washer drum, as it can degrade rubber seals and hoses" [7]. Whirlpool says vinegar's acidity "can cause damage to washing machine components, particularly rubber seals and hoses" [6]. That rules out the common advice to clean an HE washer by running a cycle with vinegar. And never put vinegar in a load or cycle that has bleach in it: Whirlpool warns that vinegar or any acid with bleach "creates chlorine gas, which can be toxic" [6].
Deciding for your machine
If your washer is under warranty and the manual says HE detergent only, the cautious choice is to use HE detergent until the warranty runs out, and to read the warranty's exclusions before switching. If you try the homemade mix, start with the measured powder, keep the dose small, and watch for the signs in the table. Your water hardness decides a good part of the result, so the next page to read is hard water and laundry. If the main reason to switch is cost, is homemade cleaner cheaper? works out the per-load saving with dated prices.
References
- LG Electronics USA, *Not Enough Suds in Washing Machine*, LG USA Support help library, June 16, 2026. https://www.lg.com/us/support/help-library/not-enough-suds-in-washing-machine--1337639883655
- LG Electronics USA, *Too Many Suds in Washing Machine*, LG USA Support help library, May 28, 2026. https://www.lg.com/us/support/help-library/too-many-suds-in-washing-machine--1337715937395
- LG Electronics, *Owner's Manual, WM3997HWA Washing Machine*, "Using Detergent/Fabric Softener" (page 20), read October 2026 in the copy reproduced by ManualsLib (no LG-hosted copy of this manual was found). https://www.manualslib.mx/manual/785300/Lg-Wm3997Hwa.html?page=20
- Samsung Electronics Australia, *SUDS Code Displays on Washing Machine*, September 29, 2021. https://www.samsung.com/au/support/home-appliances/my-washing-machine-is-showing-suds-on-the-display
- University of Florida IFAS Extension (Amanda Griffin and Randall A. Cantrell), *Homemade Household Cleaners*, FCS3319, Release Date October 7, 2025. https://ask.ifas.ufl.edu/publication/FY1449
- Whirlpool Corporation, *Should You Clean Your Washing Machine with Vinegar?*, undated (page copyright 2026), read October 2026. https://www.whirlpool.com/blog/washers-and-dryers/should-you-clean-washing-machine-with-vinegar.html
- Maytag (Whirlpool Corporation), *Stop Using Vinegar to Clean Your Washing Machine, Here's Why*, undated (page copyright 2026), read October 2026. https://www.maytag.com/blog/washers-and-dryers/stop-cleaning-washing-machine-with-vinegar.html
- U.S. Geological Survey, Water Science School, *Hardness of Water*, page dated August 24, 2026. https://www.usgs.gov/water-science-school/science/hardness-water
