Ho water heater wiring
 

I'm replacing my breaker panel. No breakers in old panel when I bought the house, so I'm chasing wires. Please correct me if I'm wrong, but if you have a red, black, white and ground, you have a 220 (double breaker)correct? Question is..... My Hot water heater has 10ga wire with only black, white and ground..so 110 correct? water heater says 240v, so why the 110 circuit? I know I need 30 amp breaker. Wires from heater go to a box on the wall THEN to wiring leading to panel. Does this have anything to do with it?.....Confused

A water heater does not require a neutral. Therefore it only requires two wires to function. The only way to know for sure the voltage is to check the name plate on the tank. If there is not one then check the actual heating elements. They will be stamped with a voltage and a wattage. Most likely it is 240 but checking the plate it only way to be sure.

Joed, It is a 240v. So, in oder to hook up a breaker to this, would I hook white and black to a double (220) 30 amp breaker...bare wire to fuse panel of course?

Please verify
 

Silly maybe, but just double checking...Red, Black, white and ground = 220...Black, white, ground = 110. Right?

Nope. WAY to over simplified.

Black, red and white is typically a 120/240V circuit, or a multi-wire branch circuit.

120V circuits are black and white if run in cable.

240v circuits are typically also black and white if run in cable. Some people run black, red and white and cap off the white, usually because they don't know any better.

what are you trying to do?

So the only time you would have a double breaker is with the red,black,white, ground combo?

allthumbs..replacing a breaker box. no breakers in old box when I bought the house and other issues with box also so just replacing

thx. just a side question, are you pulling the meter to swap or setting up a parallel panel until cutover?

allthumbs..no power to house right now. I'm putting in new 200 amp panel along with new meter combo outside as well

No, sometimes you can have a black and white on a breaker.
You need to find what is connected to the other ends of the wire.

jbfan..such as a water heater? 10ga wire...black and white hooked to double 30 amp breaker? It's a 240v heater.

Yes, just re-identify the white wire with a piece of black, or red tape.(I have used a black sharpie to do this).
This way no one is confused later.

A 240V pump circuit might be black white and ground.
A 240V older dryer circuit might be black white and ground.
A 120V multi wire branch circuit might be black red white and ground.

Like JB said, you need to find out what's on the other end of the wires. Is anything marked?

jr..nothing is marked. I'm slowly chasing wires. hot water heater is 240v black, white, and ground. 10ga wire, so.....black and white hooked to 30amp double breaker?