Third 40 amp breaker for tankless water heater

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garbo

Senior Member
GoldDigger said:
But while the faucet is open, it uses a lot more power.
For me, the biggest advantage of a tankless unit is the ability to run unlimited appliances like dishwasher and washing machine loads and long relaxing showers. But the down side is that your choices may lead you to use more energy.
That said, I am much happier with an natural gas or propane heat source than electric. And a second downside of the tankless is that the total GPM from the heater is strictly limited, showering and running the washer at the same time, or two showers at once can be disappointing. And reversing direction again, that may work well with current limited flow showers.
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Glad my house has natural gas for everything. With that huge load and a homeowner having one EV 40 amp load and electric dryer might require what a 300 amp service. No thanks.
 
G

garbo

Senior Member
Please explain the need for up to four 40 amp two pole circuit breakers. Please don't tell me electricians are running four sets of NMB cables from a panel. If Johnnie homeowner does not LOTO all four circuit breakers this would pose a shock hazard. Do any manufacturers have 4 two pole 40 amp circuit breakers inside of the units so only a 150 amp would have to be run. Read that California is no longer allowing natural gas in new houses in next ten years and parts of NY. Then 15 years later California will force existing homes to stop using natural gas. With huge loads from instant hot water heaters and one or two 50 amp EV circuits would like to know how foot dragging utility companies are going to build new generating plants, miles of high voltage lines and even upgrade the now hard to get distribution transformers. Been waiting over ten years for foot dragging PECO/Exelon to allow home owners to access thier smart meters they promised we will be able to do.
 
R

Rick 0920

Senior Member
Location
Jacksonville, FL
Occupation
Electrical Instructor
I still use a 240v time clock with (2) sets of trippers on my water heater. People are creatures of habit. My wife and I both get up at 5:00 am on the weekdays so I set the trippers to come on from 4:00 am and off at 5:00 am. so we have hot water for showering. Then they come back on at 6:00 pm and off at 7:00 pm. so we have hot water to do dishes that require hand washing. I'm sure I'm not saving that much on my electric bill but I am saving some pennies. Pennies turn into dollars.
 
H

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
garbo said:
Please explain the need for up to four 40 amp two pole circuit breakers. Please don't tell me electricians are running four sets of NMB cables from a panel. If Johnnie homeowner does not LOTO all four circuit breakers this would pose a shock hazard. Do any manufacturers have 4 two pole 40 amp circuit breakers inside of the units so only a 150 amp would have to be run. Read that California is no longer allowing natural gas in new houses in next ten years and parts of NY. Then 15 years later California will force existing homes to stop using natural gas. With huge loads from instant hot water heaters and one or two 50 amp EV circuits would like to know how foot dragging utility companies are going to build new generating plants, miles of high voltage lines and even upgrade the now hard to get distribution transformers. Been waiting over ten years for foot dragging PECO/Exelon to allow home owners to access thier smart meters they promised we will be able to do.
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They have multiple inputs and if I remember correctly, they have a warning sticker that there is more than one disconnecting means inside. My son in laws poco allows access to his meters data, but mine hasn’t yet. He has an electric tankless water heater, and he says it didn’t reduce his bill any, but his is pretty high anyway because he has a small server farm at his house! LOL!
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
garbo said:
Please explain the need for up to four 40 amp two pole circuit breakers. Please don't tell me electricians are running four sets of NMB cables from a panel. If Johnnie homeowner does not LOTO all four circuit breakers this would pose a shock hazard.
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Yes, that's exactly what we install. To heat fast-moving water, a lot of energy is required. The incoming water is heated in stages, which can be switched in or out to suit water temperature and flow.

I have installed four-40a-circuit heaters. They have four individually-controlled, high-density water-heater elements in small chambers in series, so the water gets hotter as it flows from chamber to chamber.

garbo said:
Do any manufacturers have 4 two pole 40 amp circuit breakers inside of the units so only a 150 amp would have to be run.
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I have never seen a single-circuit tankless, but one could run a single feeder to a sub-panel for one if practicable. Not too long ago, I upgraded a 200a service to 320a and a second panel just for a 4 x 40a tankless.

garbo said:
Read that California is no longer allowing natural gas in new houses in next ten years and parts of NY. Then 15 years later California will force existing homes to stop using natural gas. With huge loads from instant hot water heaters and one or two 50 amp EV circuits would like to know how foot dragging utility companies are going to build new generating plants, miles of high voltage lines and even upgrade the now hard to get distribution transformers. Been waiting over ten years for foot dragging PECO/Exelon to allow home owners to access thier smart meters they promised we will be able to do.
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It's easy to say to just make everything electric when you don't have to provide it. That's like people who say there is no pollution involved with electric cars. Where do they think the electricity comes from?
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
garbo said:
... Read that California is no longer allowing natural gas in new houses in next ten years and parts of NY. Then 15 years later California will force existing homes to stop using natural gas. ...
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For the record this is not true. Only Berkeley banned gas in new construction for a minute before a lawsuit forced them to repeal the ban. That's it.

Not that my induction stovetop isn't much more fun to cook on than any gas stove I ever had.
 
readydave8

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
hillbilly1 said:
Where on demand pays off, is where usage is very sporadic, such as a vacation cabin. Turning off the water heater when you leave means a cold shower when you come back the next weekend, or month. Daily use is where the payback is not as quick, if any.
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It takes me an hour to unload car and get organized, by then the water is hot
 
kwired

kwired

Electron manager
Location
NE Nebraska
hillbilly1 said:
Where on demand pays off, is where usage is very sporadic, such as a vacation cabin. Turning off the water heater when you leave means a cold shower when you come back the next weekend, or month. Daily use is where the payback is not as quick, if any.
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Unless you completely drained the tank, you only have to recover from room-ish temperature when you turn it on. Probably able to shower maybe half hour after you turn it back on in many cases.

And if you do forget to turn it off it isn't wasting as much as many think as MD proved.

Though it does make $$ for me in some cases, I honestly don't think many high efficiency items are worth the investment once you factor in any maintenance/repair costs if you can't perform those yourself.

Old gas furnaces seemed to last forever and when needing repairs was usually somewhat simple or inexpensive. Newer high efficiency units are efficient, but made with fairly low quality components and replacement parts have high markup most of the time.

JMO.
 
rambojoe

rambojoe

Senior Member
Location
phoenix az
Occupation
Wireman
TX+ MASTER#4544 said:
2023 NEC
Yeah, some of us 'lectricians are a real novel.
Who takes 2 showers in one day? Bathe with a friend?
Wash dishes by hand and save water. Use paper plates, we do.

If you gotta ask how much a water heater cost.....then you can't afford it. That's what they always told me when I asked.
Especially after you pay your friendly home town plumber.

I know, we spent almost a grand for a new tank of water and a new pickup for the young plumber. I shoulda never told him i was a wire twister.
Told him to call me when he needs replace burnt out bulbs.

OK, my plumber was in my electrical trade class at a high school where I taught electrical wiring, 20 something years ago.
I don't know what caused him to go left on me and take up plumbing.
Guess that's the younger gen xs on how to make more money than 'lectricians.
I still visit with him and were still good friends! Just wait till he needs me!

Thanks for reading.
Comments ACCEPTED.
TX+MASTER #4544
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This time of year with the monsoons and heat in Az- 2 showers a day is minimum...
It also helps to change into a dry shirt and undershirt before driving home..
 
kwired

kwired

Electron manager
Location
NE Nebraska
ramsy said:
Stiebel Eltron makes them
The way Americans waste water, faucets typically need 9.0 kW minimum
3.0 kW models on faucets work with a drizzle, any more pressure is lukewarm
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my guess is larry probably meant never seen single circuit unit that was rated over 60 amps?

Can't really say over certain kVA because you can get higher kVA and still be under 60 amps by going with a three phase unit or even increasing to 480 volts. I think NEC does have a 60 amp cap regardless of voltage or number of phases on this sort of item though.
 
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