wiring a hw heater

[bobski]

wiring a hw heater.
the old heater was removed 20 years ago. i dont have the old one to go by. dads 3 wire is hanging there capped off.
its wired to the breaker just fine.
of course the instructions give no clue as to what screw is pos or neg.
q: what is the classic code for pos/neg/grd?
black =
white =
red =

i flipped on the breaker and touched my test meter to red and white and got a hot reading.
any input?

the manual is worthless and has no instructions. obviously they are forcing owners to pay for electricians to get some of the cut.

 

[Dan in MI]

I would expect red, black hot, and white neutral.

Take your meter, if I am right you will get this;
White to black 110v
White to red 110v
Black to red 220v

If what you get doesn’t match skip everything I said.

 

[Hvymax]

AC doesn't have polarity. Usually there will be directions which wire goes where unless you have the old fabric insulated wires then all bets are off.

 

[GasGuzzler]

If the water is already hot, why the need for a heater?

 

[NikA]

Every electric water heater circuit I've seen runs 220V with two hot legs (red and black).

I wouldn't advise playing with 220V circuits if your level of comfort with electrical wiring is low. They're much more capable of causing a bad day than your typical 15A 110V household circuit.

An electrician is cheap compared to a hospital visit or a home insurance claim.

Then again, if you're in a rural area just getting an electrician out can be a challenge.

 

[Hvymax]

If you're comfortable doing everything else just get an electrician for the final hookup or maybe just farm the whole thing out.

 

[Fox Mike]

If the water is already hot, why the need for a heater?

I understand. I believe he is referring to a water heater. If it is hot why reheat it?

 

[Watertender]

If you are not sure it's best to get someone knows. Black and Red would be the hot wires while White is the neutral. On older systems the neutral is also the ground. Is it a new water heater or a used one? Most homes are 120/240 volts. So you would typically have 115 to 130 volts from black to white or red to white and 230 to 245 volts from black to red. Right now my house voltage is 118v and 235v because the businesses on the same power line are running their equipment.

SHUT THE BREAKER OFF WHEN WIRING IT UP AND MAKE SURE THE WIRING IS PROPERLY INSTALLED AND INSULATED!!!!!

Good luck and be safe.

 

[SWR]

I would expect red, black hot, and white neutral.

Take your meter, if I am right you will get this;
White to black 110v
White to red 110v
Black to red 220v

If what you get doesn’t match skip everything I said.

As stated above, plus, if the incoming wire is a standard older #10 or #8 romex 3 wire it may only have a black, white and ground. In that case the black and white will each have
120 volts. So you would go black to black, white goes to red on the heater and ground to ground

 

[Garth69]

wiring a hw heater.
the old heater was removed 20 years ago. i dont have the old one to go by. dads 3 wire is hanging there capped off.
its wired to the breaker just fine.
of course the instructions give no clue as to what screw is pos or neg.
q: what is the classic code for pos/neg/grd?
black =
white =
red =

i flipped on the breaker and touched my test meter to red and white and got a hot reading.
any input?

the manual is worthless and has no instructions. obviously they are forcing owners to pay for electricians to get some of the cut.

red is 110
black is 110
white is the ground wire. You will get a reading from red or black to ground wire of 110-125 volts
the reading from red to black will be 208-245 volts
the Ground wire (white) goes under the green screw.
The black goes to the water heater black.
The red goes to the water heater red.

 

[bobski]

im wiring a new elec 50gal rheem hw heater tank.

btw, im old. im one of those guys you hear about forgetting more than youll ever know.
its not fun getting old. and i dont do things often enough to remember it all.
i come here because i know there are great people who are eager to help.
thanks you all of you who give more than the classic generic (spend money) answers.
i know youre all concerned about safety, but im not that stupid yet.
heck, i packed and jumped parachutes for 22 years. i know procedures and safety.

 

[coach]

YouTube is your friend

 

[Jimbo357mag]

You should have a 220v outlet near your WH so you can plug and unplug it.

edit: oooops Guess I am a little behind times.
https://www.howtolookatahouse.com/B...eater-be-cord-and-plug-connected-by-code.html

 

[Mobuck]

When I moved into this house, the electric water heater in the basement was fed by old fashioned 'ROMEX' cable through an open fuse block screwed to a floor joist. By open I mean the wiring connections, fuse holder, and the single throw switch were not enclosed. The shut off was an old coat hanger smashed to form a hook with some sort of tape wrapped around the part one would grasp. Better not be shaky or the bare coathanger could/would touch the hot wires!!!

 

[Dave P.]

You should have a 220v outlet near your WH so you can plug and unplug it.

Why would you want to unplug it?

 

[eveled]

Make sure you do not turn power on before the tank is full of water. Or you will burn out the heating elements.

 

[coach]

Electric water heaters are generally hardwired and plug ins like an electric dryer generally aren’t allowed by code anymore.

 

[Mobuck]

We don't follow 'code' much but I've never personally seen a WH with a plug. Unless it was in something like a seasonal use cabin. Even then, I just spot a breaker/fuse box close to the WH to allow shut off.

 

[Wyandot Jim]

Why would you want to unplug it?

I have installed 4 in our house over the years and NONE had a plug.

 

[blume357]

Use a voltage tester... multi-tester is best and determine which wires give you 220-240... I presume that is what the new unit should use.
then check if there is voltage from either of those to the third wire... if there is... like 120, then don't use it. the new unit should be grounded and if there is a green ground wire use it, if not then just run a wire to a clamp on what I presume is the metal water line coming into the house, but do this close to where it is actually coming in.

the guys are probably right about the red and black being the 220-240 line but it is best to check it with a meter.

 

[Wyandot Jim]

When all else fails. Read the instructions that came with the water heater

 

[Dave P.]

When all else fails. Read the instructions that came with the water heater

That's generally a pretty boring thing to do.
Life is short, burning your house down will bring excitement into it!

 

[hittman]

Why would you want to unplug it?

For one, this conversation wouldn’t be necessary. Secondly, why not have the option even if you only use it during installation of a new water heater?

 

[eveled]

You’d still have to wire the cord and plug to the new heater. It would be an unnecessary extra cost. I’ve never seen any regular sized water heater with a plug.

 

[Dave P.]

For one, this conversation wouldn’t be necessary. Secondly, why not have the option even if you only use it during installation of a new water heater?

Extra work to wire the plug, you already have a breaker to disconnect power.
Safety wise you're adding multiple wiring connection into the circuit to potentially loosen, corrode, or resistance heat.
And finally it's not like the water heater is portable and you want to take it out and plug it in the garage any time soon.
Come to think of it though, maybe a 30-40 gallon on wheels with a garden hose connection set might be handy once in
a while.

 

[eveled]

The electricians I asked today said it wouldn’t be illegal, just dumb.

 

[Garth69]

Why would you want to unplug it?

you wouldn't. forget that.

 

[Garth69]

When I moved into this house, the electric water heater in the basement was fed by old fashioned 'ROMEX' cable through an open fuse block screwed to a floor joist. By open I mean the wiring connections, fuse holder, and the single throw switch were not enclosed. The shut off was an old coat hanger smashed to form a hook with some sort of tape wrapped around the part one would grasp. Better not be shaky or the bare coathanger could/would touch the hot wires!!!

back in the day we worked with what we had!

 

[bobski]

it was easy and its done. thanks guys.
you saved me a bundle of stupid money.

 

[Hvymax]

Why would you want to unplug it?

Things happen. Also easier to be sure it's disconnected. One less thing to deal with if you need to pull it out in a hurry. So you don't need to find someone to wire it up. I think it's a great idea to make things as "modular as possible. I have valves in and out of mine with compression fittings near the unit. If my tank decides it's going to leak I can pull the plug, shut the valves loosen 2 nuts and haul it out the door that's a few feet away. Awhile back my CO detector went off next to my wood stove. I unplugged the blower and closed the damper, pulled the pipe out of the wall and handtrucked it out the door. I suppose most people would have to call a man to deal with such issues.