# Does the hot water need to be turned on for a portable dish washer? **URL:** \ **Category:** Factual Questions\ **Created:** [April 15, 2015, 4:20am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712 "2015-04-15T04:20:22Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [April 15, 2015, 4:20am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/1 "2015-04-15T04:20:22Z")
Inside our cabin upnort we have a portable dishwasher that we never ever use. Except the other day we needed to. Hooked it up to the faucet. Wife says to turn hot water on. I say turn the cold water on as the unit has a heating element and will heat the water. I put the hot water on anyway and let the unit run as we left to drive home. But I know I’m right. Before I do any stupid experiments the next time I’m up there, what say you? The dishwasher will heat the water, right? Right! Right? ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [April 15, 2015, 7:28am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/2 "2015-04-15T07:28:11Z")
It depends on the dishwasher. The instructions for a lot of them specify to turn on the hot water, and some (especially GE models) even recommend letting the water run until all of the cold water is flushed from the lines and the water runs hot before connecting the portable dishwasher to the sink. I’m guessing that their heating element is a bit undersized and won’t get the water hot enough if the dishwasher is fed straight cold water. Without knowing the specifics of your dishwasher and what the manufacturer recommends, the safe generic approach is to always turn the hot water on. In other words, unless you know for certain which type of dishwasher you have, your wife was right. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [April 15, 2015, 11:27am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/3 "2015-04-15T11:27:40Z")
All the dishwashers I know run on the hot water, as hot water is really required for them to work. The heating element is there to keep it hot, perhaps boost it a bit, and to speed the drying. It is not intended to start with cold water. And yes it is important enough that many do recommend running the hot water in the sink first till hot water flows out. That said there should be no harm in trying. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [April 15, 2015, 11:42am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/4 "2015-04-15T11:42:42Z")
Duplicate Post ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 15, 2015, 11:56am UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/5 "2015-04-15T11:56:16Z")
Another factor is how cold is the cold water at the cabin. My obnoxiously eco-conscious dishwasher runs on cold water only. But the so-called cold feed around here is about 68F. The cold feed in a “cabin upnort” might be a wee bit chillier. At which point the dishwasher would appreciate a little help with the input temp. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 15, 2015, 12:16pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/6 "2015-04-15T12:16:33Z")
I’ve never heard of a portable dishwasher that didn’t need a hot water supply. Or any household dishwasher either. The heating element you see at the bottom of the washer is for drying. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [April 15, 2015, 1:41pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/7 "2015-04-15T13:41:42Z")
I’ve never come across a dishwasher that required a hot water feed. All the ones I’ve ever seen only require cold, there simply isn’t a hot water infeed at all. This could be a USA vs rest of the world thing of course. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [April 15, 2015, 1:51pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/8 "2015-04-15T13:51:10Z")
> [@Novelty\_Bobble](#): > > I’ve never come across a dishwasher that required a hot water feed. All the ones I’ve ever seen only require cold, there simply isn’t a hot water infeed at all. > > This could be a USA vs rest of the world thing of course. There is usually (almost always, or even always) only one water feed. I think you may be taking the hot water feed for the cold. ---
**Author:** ![elbows](https://avatars.discourse-cdn.com/v4/letter/e/b3f665/32.png) [@elbows](https://boards.straightdope.com/u/elbows)\ **Post date:** [April 15, 2015, 1:57pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/9 "2015-04-15T13:57:37Z")
You’re wrong, she’s right. Try to be gracious. (Have a portable dishwasher. When serviced the man said ‘needs hot water’, rather emphatically.) ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [April 15, 2015, 2:37pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/10 "2015-04-15T14:37:40Z")
> [@TriPolar](#): > > I’ve never heard of a portable dishwasher that didn’t need a hot water supply. Or any household dishwasher either. The heating element you see at the bottom of the washer is for drying. I’ve never seen a portable dishwasher that I would trust to leave attached and running off of a faucet for days at a time. :eek: ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [April 15, 2015, 3:04pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/11 "2015-04-15T15:04:12Z")
> [@pkbites](#): > > Hooked it up to the faucet. > > \ > > let the unit run as we left to drive home. You left it hooked up to the running water faucet and left to go home? Do you do this regularly? ETA: see BubbaDog shares my concern. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [April 15, 2015, 3:25pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/12 "2015-04-15T15:25:52Z")
> [@BubbaDog](#): > > I’ve never seen a portable dishwasher that I would trust to leave attached and running off of a faucet for days at a time. :eek: whatta you freaking out about? There is an auto shut off valve that cuts the water when the unit is finished cycling. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 15, 2015, 3:28pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/13 "2015-04-15T15:28:09Z")
> [@BubbaDog](#): > > I’ve never seen a portable dishwasher that I would trust to leave attached and running off of a faucet for days at a time. :eek: I agree. I don’t like it when my wife leaves it connected overnight. Among other things leaving the hot water on at the faucet can eventually cause a sink sprayer attachment to leak, which happened to us. However, I have seen a portable get permanently installed with a direct attachment to the water supply and drain without problems. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [April 15, 2015, 4:06pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/14 "2015-04-15T16:06:02Z")
I never even knew a portable dishwasher was a thing. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [April 15, 2015, 4:40pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/15 "2015-04-15T16:40:04Z")
> [@kanicbird](#): > > There is usually (almost always, or even always) only one water feed. I think you may be taking the hot water feed for the cold. Nope, mine clearly states in the manual that it should be plumbed into a cold water feed only. This is by far the most common practice as I understand it, [see here](http://www.whitegoodshelp.co.uk/can-you-connect-a-dishwasher-to-the-hot-water-supply/). ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 15, 2015, 5:40pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/16 "2015-04-15T17:40:05Z")
> [@Novelty\_Bobble](#): > > Nope, mine clearly states in the manual that it should be plumbed into a cold water feed only. > This is by far the most common practice as I understand it, [see here](http://www.whitegoodshelp.co.uk/can-you-connect-a-dishwasher-to-the-hot-water-supply/). Must be a UK thing (or non-US thing). I’m not sure hot water is really needed, the detergent and spraying probably work well enough, and the dry cycle is hot enough to sufficiently sterilize the dishes in the end. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 15, 2015, 5:42pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/17 "2015-04-15T17:42:56Z")
> [@Really\_Not\_All\_That\_Bright](#): > > I never even knew a portable dishwasher was a thing. Very convenient if you don’t have a built in unit. There’s no room for a dishwasher under my counters so it was a portable or washing by hand. It provides a nice rolling countertop also. Some portables are top loaders which is very annoying, you can use the top for counter space, until you need to open the dishwasher. But you can put some huge pots into the top loaders. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [April 16, 2015, 5:49pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/18 "2015-04-16T17:49:06Z")
> [@Really\_Not\_All\_That\_Bright](#): > > I never even knew a portable dishwasher was a thing. 😕 [https://www.google.com/search?q=portable+dishwasher&biw=1024&bih=609&source=lnms&tbm=isch&sa=X&ei=YfYvVfSHF4ueNr-CgfgK&sqi=2&ved=0CAcQ\_AUoAg#imgrc=jNJQIOOjr4CR0M%253A%3BHax0tFjrvGKMkM%3Bhttp%253A%252F%252Fwww.geappliances.com%252Fappliances%252Fdishwashers%252Fimages%252Fthumb\_portable\_dishwasher\_large.jpg%3Bhttp%253A%252F%252Fwww.geappliances.com%252Fappliances%252Fdishwashers%252Fportable-dishwasher.htm%3B266%3B312](https://www.google.com/search?q=portable+dishwasher&biw=1024&bih=609&source=lnms&tbm=isch&sa=X&ei=YfYvVfSHF4ueNr-CgfgK&sqi=2&ved=0CAcQ_AUoAg#imgrc=jNJQIOOjr4CR0M%253A%3BHax0tFjrvGKMkM%3Bhttp%253A%252F%252Fwww.geappliances.com%252Fappliances%252Fdishwashers%252Fimages%252Fthumb_portable_dishwasher_large.jpg%3Bhttp%253A%252F%252Fwww.geappliances.com%252Fappliances%252Fdishwashers%252Fportable-dishwasher.htm%3B266%3B312) They’re not that uncommon ---
**Author:** ![doorhinge](https://avatars.discourse-cdn.com/v4/letter/d/a5b964/32.png) [@doorhinge](https://boards.straightdope.com/u/doorhinge)\ **Post date:** [April 16, 2015, 7:05pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/19 "2015-04-16T19:05:41Z")
> [@pkbites](#): > > Inside our cabin upnort we have a portable dishwasher that we never ever use. > > Hooked it up to the faucet. Wife says to turn hot water on. I say turn the cold water on as the unit has a heating element and will heat the water. I put the hot water on anyway and let the unit run as we left to drive home. But I know I’m right. (post shortened and underline added) I can’t help with the hot/cold water issue (what does the owner’s manual say). However, I would be concerned about the age, and condition, of the hose between the dishwasher and faucet. Do you know the psi of your water supply? Hoses get old and crack. Or burst. :eek: You left this old hose under pressure and drove away. Do you have a neighbor who could check on your cabin, and turn the water off? Is there a fishing hole nearby? I might be able to spend a week upnort checking your water pressure. 😃 ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [April 16, 2015, 8:30pm UTC](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712/20 "2015-04-16T20:30:31Z")
> [@doorhinge](#): > > (post shortened and underline added) > > I can’t help with the hot/cold water issue (what does the owner’s manual say). > > However, I would be concerned about the age, and condition, of the hose between the dishwasher and faucet. Do you know the psi of your water supply? Hoses get old and crack. Or burst. :eek: > > You left this old hose under pressure and drove away. Do you have a neighbor who could check on your cabin, and turn the water off? Is there a fishing hole nearby? I might be able to spend a week upnort checking your water pressure. 😃 The dishwasher was brand new when we put it in the cabin 5 years ago and we’ve used it maybe 4 times. The hose is fine. You guys are getting a little weird about it. But nice try to get into the cabin and drink my beer. 😉 [Next page](https://boards.straightdope.com/t/does-the-hot-water-need-to-be-turned-on-for-a-portable-dish-washer/717712.md?page=2)