Verdict: False. Whirlpool says household detergents made for hand washing can generate excessive suds in a dishwasher, and it advises using only detergent made for automatic dishwashers.
Where the idea comes from
Dish soap and dishwasher detergent are both "dish detergent," and both clean the same plates. When the dishwasher pods run out, the bottle by the sink is right there. A small squirt seems too little to matter, and the dishwasher door hides what's happening inside until it's too late.
What the evidence says
Whirlpool's page on removing suds, bubbles or soap foam from a dishwasher explains the problem: "household detergents made for hand washing can generate excessive suds when used in dishwashers." Hand dishwashing liquid is designed to foam in a still sink. A dishwasher sprays water with force, which whips that liquid into foam that can push past the door and onto the floor.
The same page names two less obvious sources of foam: soap residue left on dishes from pre-washing, and spray-on dish soaps. It also warns that using too much dishwasher detergent can make sudsing worse.
If suds have already appeared, Whirlpool's recovery steps are to stop the cycle, clean up any overflow so water doesn't seep into cabinets or floorboards, remove the dishes, add about a quarter cup of vegetable or other cooking oil to the bottom of the tub, and run a Quick cycle with no detergent and no dishes. The oil suppresses the suds. Repeat if foam remains.
What to do instead
- Use only detergent labeled for automatic dishwashers: pods, powder or gel.
- If you're out, wash the few dishes you need by hand and run the dishwasher once you have detergent again.
- Scrape plates rather than washing them first. Dishes washed with dish soap and then loaded wet can carry enough soap to foam.
- Rinse off spray-on kitchen cleaners before loading anything they touched.
- Store dish soap and dishwasher detergent apart so the bottles aren't grabbed by mistake. See whether detergent goes bad if you're reaching for an old box.
Exceptions worth knowing
- •Laundry detergent is no better. It's made for a washer, not a dishwasher, and isn't an automatic dishwasher detergent.
- •A few bubbles aren't an overflow. Light foam on the tub floor after a cycle can come from residue on dishes rather than a wrong product.
- •Repeated overflow can reach parts under the tub. Some models, including Bosch, have leak protection that stops the cycle when water reaches the base pan.
- •Water on the floor or a dishwasher that won't restart after foam has cleared should be checked.
Sources
- •Whirlpool: Removing Suds, Bubbles or Soap Foam, Dishwasher (hand soap suds; pre-wash residue; oil and Quick cycle)
The short version: Dish soap belongs in the sink, not the dishwasher, even when the detergent runs out.
If foam leaked under the dishwasher or it shows a leak code afterward, call TrueFix Los Angeles at (213) 787-3989. We service dishwashers throughout Downtown Los Angeles and the rest of LA County.