Why a start button for dryers but not for washers?

My building has public coin-operated washers and dryers. The washer starts washing as soon as I put in the coins, but for the dryer there’s an additional step of a “PUSH TO START” button. Most dryers I’ve used are like this. Why would dryers need the start button when washers don’t? Or, why don’t washers need it when dryers do?

One difference between washers and dryers, is that with a washer you can open the top door and the washer keeps going.

With a dryer, there is a door-activated switch that stops the dryer when the door is opened (presumably so the clothes don’t fall out/your hand doesn’t get injured by the rapidly spinning drum).

So, let’s say you put the coins in the dryer and the door was open. The dryer couldn’t start until you closed the door. And if the door was closed, and you opened the door in the middle of the cycle, you’d need to tell the dryer to start again. The dryer can’t assume that a closed door means you want it to start up again, because maybe there’s 10 minutes left in the drying cycle, but you took the clothes out because they were already dry. It would be a waste to have the drum spin with no clothes.

I can see the logic of having a start button vs. just having it controlled by a door-activated switch.

My current washer, a front load Whirlpool Duet, a little over three years old has a Start button, I suspect most modern front loader do.

I guess that makes sense, having a start button for front-loaders then. In that case, I have another question: Why are washers usually top-loaders and dryers usually front-loaders?

Dryers dry better if the drum is mounted sideways, so that the clothes tumble over each other. Twenty or thirty years ago it was difficult to design a washer with the drum mounted sideways because the gaskets would dry out and leak. It was cheaper and easier to make a more complex drum with an agitator motion than it was to seal up a sideways mounted drum so that it wouldn’t leak.

In the last few decades we’ve had advances in rubber and gaskets as well as better manufacturing techniques that allow higher precision parts without higher costs. These have made it possible to cheaply manufacture a washing machine with a sideways mounted drum that doesn’t leak after a couple of years. The tumbling motion helps the clothes get cleaner and it only needs to fill the bottom of the drum with water (not the whole thing like a traditional washing machine) so they use much less water per wash as well.

Your el-cheapo washers are all still top loaders though.

I love the front-loading washers in my building’s laundry room, though I don’t love paying for every load. One of these days, I will have a place big enough to have my own washer and drier, and I will get a top-of-the-line front-loader.

In my building, you put the card in (for the money), and then it prompts you to press a button for whites or colors, and then it starts.

We have those now, too. I hate the card, because now I have a huge glut of quarters.

My question is why do dryers (home dryers, not commercial) have an alarm but washers don’t?

If anything, I’d rather have a notifying alarm on my washer than my dryer.

Last year we replaced both washer and dryer, and each machine has an audible “done” signal.

Nice. I didn’t know those existed. I lose 5-10 minutes on each load because I can’t tell whether the washer is done or just resting between spin cycles. I guess a front-loader would also solve that problem.

My washer and dryer not only tell me when they’re done, they play a tune.

(For some reason that sentence structure looks wrong. I think I’ve had too much coffee.)

We purchased the biggest, gaudiest carnival-side-show appliances we could find. I think they’re Kenmores. We opted for a top loader washing machine so we wouldn’t have to take our bulky bedding to the laundromat. The dryer has the same capacity as the washer, plus a spray-mist refresh cycle thingie™ that hits the clothes in the dryer about every 10 minutes and fluffs 'em up for ten or fifteen minutes.

I have not yet caught the machines cleaning up the cat boxes, but I wouldn’t be at all surprised

My Frigidaire washer and dryer both have a “done” alarm. It’s not as disturbing as a buzzer–but it does let you know when it’s done.

ISTR that the start switch on a dryer is also intended to be a safety thing in case a curious small child climbs into the front-loader. Of course, a malicious 10-year old COULD put his little brother in the dryer AND flip the switch, but it’s a lot harder to do that set of events by accident.

It’s also possible that the start button actually activates the motor’s start winding.

My mother’s ancient Maytag seems to be this way - if you just tap the start button, the motor spins briefly and stops - you need to hold it long enough for the motor to start running and switch over internally to the run winding.

Dryers have a centrifugal switch that acts as an interlock. It keeps the motor running, and is paired with a switch to sense the door opening. The push to start is a bypass to allow the motor to get up to operational RPMs that keep the centrifugal switch closed.

The lid switch in a top load washer does the same thing, but because there is a transmission in a washer instead of a belt drive, the centrifugal switch is not necessary. I have no knowledge of front loading washers, for the record.