# Electric water heater help



## panther (Oct 27, 2010)

Called out for no hot water on a 30 gallon electric water heater. Found both upper and lower elements reading 0 ohms. Replaced both elements and both thermostats. Filled unit up and let water gun out of hot side of fixtures for 10 minutes. Applied power back to heater. Waited 30 minutes still ice cold. Checked that I had 240 at upper thermostat. I do. My question is: am I supposed to have 240 across each terminal on the elements when heating? Right now I'm only getting 120 on each terminal. Probe one terminal and probe water heater tank. Water is not heating up. What am I missing? Maybe not waiting long enough to check water temp? I waited 40 minutes and still cold.


----------



## ShtRnsdownhill (Jan 13, 2016)

should have 240 across the element terminals..


----------



## tim666 (Mar 11, 2014)

Have you checked amps?


----------



## Qplumb (Dec 19, 2015)

If you test one terminal on element & ground to water heater you will only get 120v. Test with volt meter both terminals together you should get 240v on whatever element is heating. If you only get 120v the breaker is bad in the panel box.


----------



## dclarke (Dec 22, 2012)

Is it a 240v WH ? Sounds like you lost a leg to me.


----------



## Debo22 (Feb 15, 2015)

Did you push the red button?


----------



## Tommy plumber (Feb 19, 2010)

Does the house have a basement? Or is it a slab-on-grade construction?


----------



## KoleckeINC (Oct 22, 2011)

Didja take the wires off when you ohmed them out? If you've never done it before best bet is to call the 1800#. And yes push the red button. Or You've wired it wrong.


----------



## ShtRnsdownhill (Jan 13, 2016)

its always nice someone asks for assistance then disappears....


----------



## panther (Oct 27, 2010)

Found it guys. Thank you very much. I did wire it back up wrong. One wire in wrong spot. May be time for new glasses.


----------



## panther (Oct 27, 2010)

KoleckeINC said:


> Didja take the wires off when you ohmed them out? If you've never done it before best bet is to call the 1800#. And yes push the red button. Or You've wired it wrong.


That's what happened. Two wires went to the wrong place. Thanks for the help. After I read your reply, I checked my wiring again.


----------



## justme (Jul 4, 2012)

here's a reminder on how test and wiring 

http://waterheatertimer.org/How-to-test-water-heater-element.html


----------



## Toli (Nov 7, 2015)

How can an element show 0 ohms? Infinite ohms, sure. But 0? What am I missing?


----------



## ShtRnsdownhill (Jan 13, 2016)

once an element burns out, its like a cut wire, it will show no ohms or no resistance...


----------



## Toli (Nov 7, 2015)

ShtRnsdownhill said:


> once an element burns out, its like a cut wire, it will show no ohms or no resistance...




When an element burns out the ohms will be extremely high, not zero.


----------



## ShtRnsdownhill (Jan 13, 2016)

Toli said:


> When an element burns out the ohms will be extremely high, not zero.


only if the burned out coil makes contact with the outer shell of the heating element, otherwise its like holding the 2 leads on the ohm meter 2 inches apart and not touching, there is no reading because the coil is broken in 2...if you had a 3 ft piece of copper and you had the ohm meter on both ends you would read continuity on the ohm meter, now have someone cut the wire in half, no more reading..thats what happens when the coil wire burns out and breaks in the heating element..


----------



## ShtRnsdownhill (Jan 13, 2016)

Toli said:


> When an element burns out the ohms will be extremely high, not zero.


read number 4...............
*How to Determine Which Water Heater Element Is Bad?*

by Robert Korpella 

 Email
 Facebook
 Twitter
 Pinterest
 Reddit
 Google+
 Turning on the faucets for a relaxing shower only to find tepid or icy water makes for a frustrating experience. When an electric hot water heater’s elements short out or burn through, cool water is the result. Typically, the lower element goes first, but that’s not always the case. Fortunately, a few quick electrical tests reveal which element you must replace in order to restore hot water to your home.




*1*

Turn off the power to the electric hot water heater. Some units are wired to plug into a wall socket, and power is shut off simply by unplugging them. Most units are hard wired directly into the home’s circuitry, so turn the breaker for the hot water heater to “OFF” at the home’s main electrical panel.

*2*

Remove the two wires connected to the water heater element and push them aside. Unscrew the mounting hardware with a screwdriver, slip the wires out and bend them out of your way.

*3*

Set the multitester to measure ohms, or resistance. The ohm key is typically written in green and identified with an omega sign on the tester. Set the scale to the lowest readings, usually “RX1K” or “RX1.”

*4*

Touch a probe on the multitester to each screw on the element. If you get no reading, or a maximum reading, the element is bad. Elements do have some resistance, so a reading of 10-16 ohms is normal, with higher ohm readings for 3,500 watt elements and lower readings for 5,500 watt elements. The wattage of your element is printed on the plastic block between the two screws where the wires were attached.

*5*

Touch one probe to a screw on the element and the other probe to bare metal on the water heater. Any ohm reading or slight movement of the multitester’s needle indicates an element that has shorted out. Check each screw on both elements.

*6*

Touch one probe to the element screw and the other to the metal frame of the element (but not to the other screw). Any needle movement or reading indicates an element that has shorted out. Check each screw on both elements in the same manner.


----------



## tim666 (Mar 11, 2014)

Maximum reading would be the infinite as Toli said or open line as my ohm meter reads


----------



## ShtRnsdownhill (Jan 13, 2016)

Correct..Toli is half right..


----------



## Tommy plumber (Feb 19, 2010)

So in a residential service call for 'no hot water', do you guys replace just {1} element?

And if one of the t-stats is determined to be bad, same question. Do you just replace {1} t-stat?


----------



## Qplumb (Dec 19, 2015)

Tommy plumber said:


> So in a residential service call for 'no hot water', do you guys replace just {1} element?
> 
> And if one of the t-stats is determined to be bad, same question. Do you just replace {1} t-stat?


I replace both elements and thermostats always. Prevents any chance of callback. I do the same on commercial electric water heaters.


----------



## tim666 (Mar 11, 2014)

ShtRnsdownhill said:


> Correct..Toli is half right..


If you touch the ohm meter probes to each other you have zero ohms or absolutely no resistance


----------



## Toli (Nov 7, 2015)

ShtRnsdownhill said:


> read number 4...............
> 
> 
> *4*
> ...




Thanks, but that proves my point. 

0 ohms is like touching your test leads together. "No reading" as said above doesn't mean 0. It means your meter doesn't move off of "OL" (or whatever your meter does to indicate an open circuit.)


----------



## Green Country (Mar 6, 2009)

Toli said:


> Thanks, but that proves my point. 0 ohms is like touching your test leads together. "No reading" as said above doesn't mean 0. It means your meter doesn't move off of "OL" (or whatever your meter does to indicate an open circuit.)


You are correct Toli. 

You can get a lower reading of the element is shorted out though. I don't remember if I've ever seen it at 0, but definitely less than about 13 which seems to be the typical resistance. 

You'll get 0 if you don't take the wires off.


----------



## Toli (Nov 7, 2015)

Green Country said:


> You are correct Toli.
> 
> You can get a lower reading of the element is shorted out though. I don't remember if I've ever seen it at 0, but definitely less than about 13 which seems to be the typical resistance.
> 
> You'll get 0 if you don't take the wires off.




Agreed.


----------



## KoleckeINC (Oct 22, 2011)

Downhill sounds like redwood.


----------



## ShtRnsdownhill (Jan 13, 2016)

Toli said:


> Thanks, but that proves my point.
> 
> 0 ohms is like touching your test leads together. "No reading" as said above doesn't mean 0. It means your meter doesn't move off of "OL" (or whatever your meter does to indicate an open circuit.)


your arguing the same side of the coin.. you can get both 0 and infinite reading on a bad element...and thats what I stated.. so whats the big issue?


----------



## wyrickmech (Mar 16, 2013)

0 resistance simply means exactly that a full circuit. The larger the resistance the higher the ohms reading.


----------



## Toli (Nov 7, 2015)

ShtRnsdownhill said:


> your arguing the same side of the coin.. you can get both 0 and infinite reading on a bad element...and thats what I stated.. so whats the big issue?




First of all I'm not arguing. Second of all 0 ohms and infinite ohms are not the same thing.


----------



## justme (Jul 4, 2012)

KoleckeINC said:


> Downhill sounds like redwood.



Wrong , Redwood knows how to test elements and can clearly tell you how to test them.


----------



## Toli (Nov 7, 2015)

ShtRnsdownhill said:


> your arguing the same side of the coin.. you can get both 0 and infinite reading on a bad element...and thats what I stated.. so whats the big issue?



Actually you said "once an element burns out, its like a cut wire, it will show no ohms or no resistance..."

That is not correct. A cut wire will show infinite ohms.


----------



## ShtRnsdownhill (Jan 13, 2016)

Toli said:


> First of all I'm not arguing. Second of all 0 ohms and infinite ohms are not the same thing.


correct, thats what ive been stating all along...


----------



## tim666 (Mar 11, 2014)

ShtRnsdownhill said:


> once an element burns out, its like a cut wire, it will show no ohms or no resistance...


It's alright to say "Oops, you're right Toli, i was wrong "


----------



## ShtRnsdownhill (Jan 13, 2016)

tim666 said:


> It's alright to say "Oops, you're right Toli, i was wrong "


Touch a probe on the multitester to each screw on the element. If you get no reading, or a maximum reading, the element is bad. Elements do have some resistance, so a reading of 10-16 ohms is normal, with higher ohm readings for 3,500 watt elements and lower readings for 5,500 watt elements. The wattage of your element is printed on the plastic block between the two screws where the wires were attached.


reread till you understand....


----------



## tim666 (Mar 11, 2014)

If you are getting zero then you have both probes on the same screw


----------



## ShtRnsdownhill (Jan 13, 2016)

tim666 said:


> If you are getting zero then you have both probes on the same screw


if the inner coil shorts out against the outer metal shell of the element, then yes it will be 0 just like both probes are on 1 screw, its shorted out against the casing, so you will get the same reading as if you touched the 2 probes together,,we are saying the same thing , just 2 different ways...


----------



## tim666 (Mar 11, 2014)

I reread and reread your post that was questioned where you said that a burned out element would be like a cut wire and have no resistance or zero ohms. Which a cut wire would have infinite resistance now you say that you meant if the copper coil sheared off on both sides and made immediate contact at the casing.


----------



## ShtRnsdownhill (Jan 13, 2016)

tim666 said:


> I reread and reread your post that was questioned where you said that a burned out element would be like a cut wire and have no resistance or zero ohms. Which a cut wire would have infinite resistance now you say that you meant if the copper coil sheared off on both sides and made immediate contact at the casing.


what does this say? in your mind or understanding

*4*

Touch a probe on the multitester to each screw on the element. If you get no reading, or a maximum reading, the element is bad. Elements do have some resistance, so a reading of 10-16 ohms is normal, with higher ohm readings for 3,500 watt elements and lower readings for 5,500 watt elements. The wattage of your element is printed on the plastic block between the two screws where the wires were attached.

a bad element will show either or of the above, granted not at the same time..if you put an ohm meter on the 2 screws and get a reading give or take around 10 to 16 ohms the element is good, anything way up or down of those readings element is bad.....cant get any simpler than that to explain..tried to give an example, but I guess its not able tobe understood..:confused1:

in its basic form, an ohm meter shows continuity ..and then you can measure resistance on that line.....so, if the element burns out it will either show no continuity( the dial wont move or digital will show nothing)..or if the coil shorts against the element casing almost no resistance( as you might be labeling infinite ohms)( the dial will fly all the way over or the digital will show no resistance, as the coil isnt in play anymore) as its now a dead short between the 2 screws...


----------



## tim666 (Mar 11, 2014)

We are obviously speaking two different languages. Nobody questioned that the ohms would be different on a bad element. What was questioned was zero ohms


----------



## Toli (Nov 7, 2015)

> ....or if the coil shorts against the element casing almost no resistance( as you might be labeling infinite ohms)
> 
> 
> > OK, for the last time- no resistance is NOT infinite ohms.


----------

