Does this device exist?

A relay is all you need. Remove the coil & rewind with a small number of turns of thick wire. Now when enough current goes to the dishwasher, the water heater is turned off. I'd use 2 relays the same, one to experiment, the 2nd for the final unit.

NT

It is called a "Point-of-Use" water heater.

Now, some Basic Electricity 100:

The POU *STORAGE* water heater draws twelve (12) amps at rated nameplate. The typical dishwasher with an exposed internal heating element is rated at eleven (12) amps.

We keep a Bosch that does not have an exposed element but does have an on-b oard flash heater, and so also uses 12 A.

There are two solutions that come immediately to mind. Use a at true instan t-hot for your sink water - these devices, typically, run under seven (7) a mps. Then, even if you feed the dishwasher from the same line, you would be in no danger of popping a 20 A breaker - the minimum that should be in a k itchen in any case.

Or, run a second line directly to the dishwasher. Which is the way it shoul d be done in any case.

Note that instant-hot water heaters will give you all the hand-use water yo u want, and nicely support a dishwasher such as it will require minimal use of its on-board heater.

Peter Wieck Melrose Park, PA

If you are in North America, and that is a "duplex" receptacle, its likeley to be an "appliance" outlet, that is, each side wired to a separate breaker. Check the labelling in the box to find out, or measure the voltage between the two "hot" connectors. 230V means you're good to go.

The good folk in Quincy, MA are recoiling in horror!

DO NOT EVEN CONSIDER this option, most especially if you have any other living things in your household.

Peter Wieck Melrose Park, PA

You may be correct about that being on two circuits. I have my doubts because of the age of the house and because of other flaky things found in his house, but since the wiring SHOULD have been inspected, maybe you are correct. I'll have my brother check. Eric

Point of use water heaters don't provide enough hot water to wash a load of dishes. But a small water heater will. I use one in my shop. My brother is not gonna add another line because of the expense. I can buy a delay relay that is made for shop vacuum systems that is plug and play, but these devices only delay the turning on by 7 seconds of a load. I need to keep ne load off while the other is on. Eric

at eleven (12) amps.

-board flash heater, and so also uses 12 A.

ant-hot for your sink water - these devices, typically, run under seven (7) amps. Then, even if you feed the dishwasher from the same line, you would be in no danger of popping a 20 A breaker - the minimum that should be in a kitchen in any case.

uld be done in any case.

you want, and nicely support a dishwasher such as it will require minimal u se of its on-board heater.

An instant water heater that only takes 7A, whether at 110 or 240v, is not going to produce a lot of hot water. Water heating is energy intensive.

And no dishwasher here is designed to support hot water intake.

NT

I see you offer zero basis for this claim. It's just a basic demand management unit.

My dishwasher said to hook it to the hot water line.

in what country?

In the good old USA .

Copy and paste from online manual.

WATER SUPPLY REQUIREMENTS ? This dishwasher has a water heating feature and also requires a connection to a hot water supply line. ? A hot water line with 20 to 120 psi (138 to 862 kPa) water pressure can be verified by a licensed plumber.

US washing appliances are quite different to ours. Why I don't know.

NT

Especially when many of the US appliances are not made in the US any more.

The breadth of your ignorance never fails to amaze me. My dishwasher in the kitchen connect to the hot ware line. And it will NOT run with cold water.

My dishwasher has internal heat for the final rinse (to meet a NSF hot-water final rinse temperature requirement). It worked fine, both washing and rinsing, on cold water (when my water heater was on vacation...) though it is intended to be plumbed into the hotwater line.

During the water heater replacement, I removed about 20 feet of rusty iron pipe, replumbed with copper, and the flow is a lot better now.

Assuming the wiring is correct: In the USA a standard duplex receptacle is wired for 120 volts. A receptacle wired for 230 (240) will not be a duplex.

Ed

Eric:

a) Unless you are using a dishwasher from the POS Manufacturing Company, Ha ngsen, China, it *DOES NOT NEED* very hot water to operate. The on-board he ater (NSF requirement) will manage the difference between incoming water t emperature and that necessary to clean the dishes. b) And, if you are using a dishwasher made in the last 3 - 5 years, and fro m a reputable manufacturer, it will use very little water relative to hand

-washing. So, if a POU device will be adequate for doing dishes in the sink , it will be equally adequate to supply a dishwasher.

As a point of comparison, our 10-year old Bosch (made in Tennessee) uses le ss than 4 gallons of water in the "Scrub-Paint-From-a-Board" mode, and abou t 0.870 KW of energy. Nor do we have to pre-wash the dishes. Anything small er than cherry and softer than a hard nut will be handled. Advanced for its day, commonplace now.

Peter Wieck Melrose Park, PA

t going to produce a lot of hot water. Water heating is energy intensive.

Another hip-shot going wild.

a) The ECOSmart line here in the USA produces a 7A under-sink unit that pro duces 1.3 GPM (4.92 LPM) at a 50-degree F (10 C) rise. The idea is not to s cald a user (110 F and up).

b) Dishwashers rated by the NSF (National Sanitation Foundation) will do th e final rinse for a residential dishwasher at 165 F (74 C) minimum. Some go to 180 F as an option. Yes, they are to be required to be connected to the hot water line, if only to reduce stress on the internal heater.

Peter Wieck Melrose Park, PA

Nope, no basis whatsoever, other than the National Electrical Code as published by the NFPA out of Quincy, MA.

Peter Wieck Melrose Park, PA