Electric w/h - Contractor Talk - Professional Construction and Remodeling Forum

Philly Dude · 08-03-2009, 11:36 PM

Can an electric w/h run off of 240v with just a red and black wire and no neutral? Seems like common sense to me that there has to be a neutral wire. Whoever this w/h was running for the last 6 months w/o a neutral wire. It just had a red and black going to a 20 amp double pole.

mrmike · 08-04-2009, 05:33 AM

Yes, a 220v W.H. needs no neutral as the thermstats are wired 220v as the elements, so there is no need for it. But it must be grounded.

A neutral completes a circuit for 120v. For example a dryer or range which have 120v for their controls, so therefore they have the 2 hots (220v) & a neutral & ground.

bwalley · 08-04-2009, 06:35 AM

Quote:

Originally Posted by Philly Dude

Can an electric w/h run off of 240v with just a red and black wire and no neutral? Seems like common sense to me that there has to be a neutral wire. Whoever this w/h was running for the last 6 months w/o a neutral wire. It just had a red and black going to a 20 amp double pole.

Common sense???

On a 240v circuit, what are you going to do with the neutral?

240v Water heaters do not need a neutral, they need 2 hot legs, and a ground.

Seems to me you are working in an area you have no clue about, I hope you aren't working on electrical or water heaters for clients.

Plumber_Bill · 08-04-2009, 07:41 AM

Don't mess with a water heater if you don't know what you're doing.

This post mentions 240 and neutral ... no neutral in a water heater circuit, ( Just L-1 & L-2 and ground) but you must look at the plate for a small 6 or 10 gallon heater might be a 110 v heater then there would be neutral, hot and ground. My advice would be to anybody servicing these heaters. Learn to use a volt, amp and ohm meter, turn off the power before you put your fingers in there. Check for grounded elements (they can continue to make hot water on the un-switched side). Be very alert if the customer said they pushed the red button.

Service guys here is a gift for your tool box. Print the attachment out on heavy paper.

protechplumbing · 08-06-2009, 10:49 AM

All you have to do to check for a grounded element is turn down both stats and check you incoming lines for amperage.

Quote:

Originally Posted by Plumber_Bill

Don't mess with a water heater if you don't know what you're doing.

This post mentions 240 and neutral ... no neutral in a water heater circuit, ( Just L-1 & L-2 and ground) but you must look at the plate for a small 6 or 10 gallon heater might be a 110 v heater then there would be neutral, hot and ground. My advice would be to anybody servicing these heaters. Learn to use a volt, amp and ohm meter, turn off the power before you put your fingers in there. Check for grounded elements (they can continue to make hot water on the un-switched side). Be very alert if the customer said they pushed the red button.

Service guys here is a gift for your tool box. Print the attachment out on heavy paper.

Archania · 08-07-2009, 01:24 PM

When I have installed them, I just run some 10/2 NM to it. Just use the white as the other hot. And yes, ground it!

Philly Dude · 08-07-2009, 11:17 PM

Thanks for the replies. The w/h has 2 elements and one of the has short circuited. I will be calling the manufacturer tomorrow to get either a new element shipped out or a completely new h/w.

bwalley · 08-08-2009, 09:29 AM

Quote:

Originally Posted by Philly Dude

Thanks for the replies. The w/h has 2 elements and one of the has short circuited. I will be calling the manufacturer tomorrow to get either a new element shipped out or a completely new h/w.

Most of the time an element goes bad because it has an open in it, not because of a short, I have never seen one short circuit.

Why is it whenever there is an issue with something electrical, people always call it it short circuit?

BTW an element can be bought at any supply house, or even HD or Lowes, they are not proprietary, all you need to know is the wattage and voltage of it, most likely it is the lower element that went out.

Why not just call someone that knows what they are doing? if this is a clients house you have done them a major disservice by not getting their water heater diagnosed and repaired within 1 hour.