Dishwasher hot water usage

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When a dishwasher uses hot water from a hot water pipe, does it know it should wait till the hot water runs hot, or does it just go ahead and get whatever comes out of the pipe?
If a dishwasher has the capability of heating its own water, would it make sense to connect it to the cold water? If it gets cold water from the hot water pipe, then, by the time it finishes getting the water it wants, the hot water pipe would start to get hot, which would be wasted while waiting for the dishwasher to use it again. That problem would be solved by connecting it to cold instead of hot, so no hot would ever be wasted. Right?
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Beter off to run the hot water in the sink to heat it first imo

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It depends on the dishwasher and the cycles. Some dishwashers have special cycles to heat the water if it is not hot enough. Others do not. Then you would be washing in cold water which is about useless. Even on the dishwashers with the special cycles, the regular cycles may not heat the water. They are all made to hook up hot water

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I believe that some European dishwashers are made to hook up to cold water since in some areas they often have smaller hot water supplies.

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I believe that some European dishwashers are made to hook up to cold

that because europeans often have tankless water heaters.
my old bosch had a fantastic water heater built in.
unfortunately the bocsch was the least reliable of any dishwaser I have ever had and dead last in reabilty by consumer reports.
now that isnt the worst its parts cost a fortune, all service is difficult, because of the design, and it breaks way too much,
thats why mine went to the trash.
I am going to insulate the hot water lines to improve performance of the whirlpool dishwasher. its just one year old and honestly a piece of scrap. heck even the silverware basket broke.
too bad its hard to find good products anymore:(
the chinese guys are good at producing low priced stuff, but quality isnt one of their concerns:(
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Just use it as directed in the instructions, in other words, don't worry.
It will or will not heat water as it is designed. They are all designed to connect to the usual domestic hot water and expect that there will be some cold water come in first. Don't worry. I believe almost all of them today have their own heater to increase the temperature above the usual domestic hot water temperature. Of course no matter if the water is heated before it gets to the machine or after, you are going to pay for heating it either way. If you have an electric water heater it will be the exact same price if you have a cheaper source for your domestic hot water it will cost just a little more, but not enough to justify increasing the domestic temperature setting.
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On Aug 7, 2:16pm, snipped-for-privacy@columbus.rr.com wrote:

I agree just dont think about it, mine heats the HW until its at a certain temperature, some dont, messing with cold-hot is a waste of time. You want to save money, do it by hand.
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Actually, doing dishes by hand typically uses a lot more water (and hot water) than modern dishwashers so long as you run the dishwasher reasonably full.
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To clarify, the dishwasher in question is presently always set to use the cycle that heats the water, because the water is never reliably hot. Even if we run the water to get it hot, it doesn't stay hot very long, because the pipe is not insulated, and goes under the slab foundation.
Ideally, we should set it up with some kind of switch to be able to switch back and forth between hot and cold water, so we can experiment with different cycles etc., to see which get the dishes cleanest, and which result in higher energy bills. Also, this dishwasher can take hours. But even if we put it on its shortest, non-heating cycle, it still seems to take hours. Or at least a long time.
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No. Leave it connected to the hot water. Go read a book or remove your spouse's clothing. Either of these is a much better way to expend time & energy.
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If you feed it cold water, it will take longer to heat the water, slowing the cycle. Run the water before you start it till the water is hot to speed the wash. If you heat water with cheaper fuel (Gas), it will cost less to use the hot water supply. Dishwashers may not need to heat the water after the first cycle, as one hot cycle should wash and sanitise, and rinsing doesn't need the highest heat.
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It seems to have several phases. A preliminary wash that disposes of garbage by sending it to the in-sink erator. Other phases after that.
Here is what I think might be happening in the phases after the first: The water in the pipe is no longer hot at the start of the phase. The dishwasher draws that cooled water from the pipe. The house water heater replaces that water in the pipe with hot water. The dishwasher proceeds with that phase, starting by heating the cooled water, while the hot water in the pipe cools. So the hot water in the pipe would waste its heat while at the same time the dishwasher would be wasting energy to reheat water whose heat was already wasted.
Electricity around here is almost as cheap as natural gas. Some months it might actually be cheaper.
Those are the reasons why I think it might be a good idea to try switching the dishwasher to use cold water.
It's true that it would take hours. But it takes hours anyway. An extra hour isn't likely to be a big deal. You would want to run it while you sleep or while you're not home or whatever.
Regardless, it does a good job of getting the dishes clean.
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THAT makes no sense at all. Gas is measured in therms, while electricity is measure in kilowatt hours. Just because your gas bill and electric bill might be around the same amount has nothing to do with the basic cost of gas and electricity.
Electricity is nearly always a more expensive way to heat anything compared to gas (or oil or propane)
JK
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Unless you live somewhere where you get cheap hydro-generated electricity.
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Are the rates really that better? We pay a little over 11 cents a kilowatt hour where I am (Wisconsin), which is cheaper than many other places, but I would be curious if it is really that much less where hydro is prevalent.
JK
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writes:> Are the rates really that better? We pay a little over 11 cents a

There are places where electricity rates are below 5 cents per KWH. Some of it comes from hydro and some from nuclear. Meanwhile, natural gas has been skyrocketing for the past few months.
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In central VA, we pay a little less that 8 cents during the summer air condioning season and about 6 cents during the winter. Heat pump users can get "budget billing" with a fixed monthly charge.
Our power comes from a mix of coal fired plants and nukes.
There may be a few "peaking" plants that use oil or NG but there are also some coal fired plants that aren't owned by the same folks that distribute the power.
Some of this may change because (as happened in California) our local utility promised to keep rates down in exchange for permission to sell off its power plants. The "modern" pattern is for a particular company to own distribution systems in one area and power plants in another area and high voltage links in still other areas. Essentiallly, these three aspects of the costs to the consumer will be controlled locally by three different companies.
You can "look it up" but for year and years in most places "hydro" is used mosly for "peaking" rather than base load. Base load plants (coal and nuke) are often placed on the lakes created by "hydro" dams.
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Here in CT we are paying 18
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dishwashers only heat water if put in the sanitize setting.
Incoming water should be 140 or more degrees and be close to the source.
s

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On Thu, 7 Aug 2008 15:11:50 -0500, "Steve Barker DLT"

My dishwasher is hooked up to the hot water line only. Our gas water heater is set to 125 degrees, so the dishwasher heats it to higher temperatures. Cold water washing seems to be the trend, but I'm not convinced cold water kills pathogens as good as hot water. My washer does not have a "sanitize" setting--I thought it sanitized at whatever settings.
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