Did some work for a customer wherein I had to shut off the main water to the house for a while. House was on well water, no main shut-off; had to kick the pump breaker and de-pressurize tank and house to shut it all down.
After I turned everything back on, one of her elec water heaters ( a small 19gal for the kit only) was not producing hot water. I checked it out: had power (120V unit), reset button was not popped, had proper voltage across the element, but no heat. I then shut it down and checked the element w/ my ohmmeter and read very little resistance (micro-ohms). So I determined that the element had somehow shorted/burned up (did the tank siphon out when I drained the system and fry the element?). Odd things was, the breaker had not kicked and I still had normal voltage to the unit. In any case, my DMM said the element was bad, so I said I’d replace the element.
Next day, she calls and tells me the hot water is working again.
??
It’s now been a week and she reports the hot water is intermittent–has it in the morning, usually, but not at night. This is a SINGLE element 120v 19 gal water heater using a 1500w element.. Whirlpool, standard 4 yr-old unit from Lowes. How can it be intermittently giving heat (I checked it when it was ‘not-working’ and saw voltage from the t-stat to the element) and how can a bad element be ‘sometimes’ good? And how can my briefly shutting down her water have caused this problem?
Anyone have any ideas?
Replies
The tank bled down while you had the water off, element died.
Now the ghost of the element is haunting you.
You need a new element or an Exorcist.
Joe H
Yeah, a burned out element can sometimes heat the water through electrolysis. But the amount of heat is relatively small, so recovery time is quite long.
If your view never changes you're following the wrong leader
Dan, that sounds like exactly what's going on...and would probably explain my reading of a few micro ohms across the element (I did disconnect it before I measured it). HO says it's taking about 1/2 a day to heat the water. BUT ELECTROLYSIS! So she's potentially got hydrogen and oxygen building up in her tank right now?? Have you actually experienced this before?
I am speculation that the element burned in two and one end is randomally making contact with the sheath (ground).
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Micro ohms is essentially a short, which would make for very high current, tripped breaker and probably smoke. Or do you mean megohms? which equals almost no current and no heat.I would lay odds on a defective element.Nobody gets in to see the wizard...not nobody...not no how!
According to my calculations you should be reading 9.6 ohms across the element.
1500watt/120volt=12.5amps power=amps x volts
120volts/12.5amps= 9.6ohms volts = ohms x amps
I would suspect the element has gone iffy or you have a weak connection somewhere.
I figured the tank bled down which would have fried the element...(and I didn't even know about it---it's located in a concealed cab. space next to the stove). There's no shut-off to the tank or on anything at all in the house. 9.6 ohms is exactly what I read on the new element I bought for the tank. But why doesn't the bad element read infinite ohms if it's open/broken? By the way, ohms is a measurement of resistance, but higher ohms means LESS or MORE resistance? ...
Higher Ohms= more resistance
0 (zero) ohms = no resistance (sw closed)
infinite ohms = open line (sw open). DMM may say OL.
I would disconnect the element and re-measure to rule out a bad connection somewhere before trying to remove the old element.
If the pump is lower then the water heater you siphoned out the water when you bled the pressure tank remember the cold water heater fill has a tube that reaches the bottom of the tank, works the same way you siphon out gas out of a car. You must of opened a valve in the house to bleed out the water.
So the element is probably almost burnt out. If that turns out to be the case talk to her about a shut off at least on the cold line to the heater.
Wallyo
Edited 2/4/2008 1:50 am ET by wallyo
the wlemrnt is damaged or the thermostst is sticking...
change both and be done with it...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Do you know of a good internet source for wlemrnts?
If your view never changes you're following the wrong leader
did you say watermelons????
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!