Why do washing machine timers take longer than is displayed?

September 20, 2018 9:06 PM

At many points in my adult life I’ve used front-loading washing machines. Invariably -invariably!- the timers on the washing machine run slightly slower than the actual clock time. One example: I started a load the other day that was supposed to finish in 30 minutes. I came back after ~35 minutes (33 minute timer + slosh) and still had 3 minutes to go. Is there a design reason for this? Do coin-op washers just have bad timers?
posted by Going To Maine to Home & Garden (12 answers total)

Best answer: It's the amount of water pressure; both hot and cold. It takes an unpredictable amount of time to fill the washer. Depends on how many other washers (clothing/dish) are running, how many people are taking showers or filling the sink.
posted by zengargoyle at 9:25 PM on September 20, 2018 [13 favorites]

Best answer: It’s not just a coin-op thing; the washer in our house is horrible at this. It seems to be pretty accurate until about the last 5 minutes, which take 10-15 minutes.
posted by Ideal Impulse at 9:26 PM on September 20, 2018 [1 favorite]

Best answer: This happens with the domestic top-loader where I am (5~10 mins), and my guess is also variable water pressure.
posted by quinndexter at 9:35 PM on September 20, 2018

Best answer: Also, fuzzy logic. It's adjusting stuff after you start based on what's going on with the load (especially newer machines).

nb: if you have a fancy rice cooker whose timer doesn't match reality, fuzzy logic is probably why!
posted by brainmouse at 9:50 PM on September 20, 2018 [10 favorites]

What Ideal Impulse said.
posted by pompomtom at 10:23 PM on September 20, 2018

Best answer: From one company:
Your clothes washer time to complete a cycle is based on the type of laundry detergent you use, the size and type of your load, which cycle you chose and temperature and pressure of your water.
So, for instance, if you use too much detergent, it will “oversuds” and take longer to rinse out of your clothes. (Some brands will flash “Sd” or “Sud” on the indicator when this happens. To avoid, use the recommended amount of HE detergent).
If the load is unbalanced, say, due to you only washing one item or particularly a bulky item, your washer will keep trying to rebalance itself and that will add minutes to the process.
posted by typify at 11:15 PM on September 20, 2018 [3 favorites]

Agh, basically what brainmouse said.
posted by typify at 11:16 PM on September 20, 2018

I assign a very low credibility to any statements from manufacturers about things like this since they're usually written by the marketing people. After many years working in software, I believe the actual answer is more like "we have to display some numbers that count down but there are no accuracy requirements." If the washer were tuning itself to your water and detergent and what style of jeans you're washing, it'd get more accurate with time but that hasn't really been my experience.

Strangely, our (not that-) old Whirlpool front-loader died the true death a couple weeks ago (bearings are no longer a replaceable part!) and was replaced with a brand-new similar model. This one seems absolutely correct in its predictions. Of course, we've only washed three or four loads, so it could become wildly inaccurate in the future.
posted by Gilgamesh's Chauffeur at 6:09 AM on September 21, 2018 [2 favorites]

I think it's actually more of a minimum, not an estimate. As in, "don't bother to come back before this time." Our home front-loaded will finish a small load in the stated time, but very heavy loads that require more washing and longer cycles can take 25 minutes longer than the 54 minute minimum time. This machine is a 10-year-old Kenmore/Whirlpool model, for what it's worth.
posted by wnissen at 9:22 AM on September 21, 2018

Same reason it takes 5 minutes for a software update to complete when it reads "less than a minute"
posted by terrapin at 10:09 AM on September 21, 2018 [2 favorites]

I recently sold my used washer to someone on Craigslist. I got a text shortly after accusing me of selling him a broken washer and I was confused. It had worked fine for me.

It turns out that my new-ish washer has a sensor mode before it starts where it weighs things, does a test spin, checks the clothing level, etc. So it doesn't start immediately after you push the Start button. I followed up with the buyer and he confirmed that it started working after the brief sensing cycle.
posted by tacodave at 3:41 PM on September 21, 2018

If you really want to find out, and have the time on your hands, you could sit there and watch exactly how fast the timer decrements. Use the timer feature of your cellphone clock and set it to the same time as the machine when it starts. Then you can see, minute by minute if the two match or not. You might find that it matches well during certain parts of the cycle and not others. For example you might find that the water filling periods vary depending on water pressure. Or the spin cycle depends on how long it takes to wring out the last drop according to the size of your load. This would tell you if the clock is really running uniformly slow or whether the smart features of the washer are adjusting time according to the load.
posted by JackFlash at 4:24 PM on September 21, 2018