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| Heating element resistance question | Rate Topic |
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| Posted: Sun Mar 21st, 2010 11:59 pm |
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1st Post |
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anven Member
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Hi, I recently had to repair my 14 year old electric water heater (Kenmore), and as a result found something that struck me as strange. The upper heating element resistance read 7.5 Ohm. Ohm's law tells me thats a 7680 Watt element. Having read some article online, some claim that 7.5 ohm reading is normal, but I do not know why. Can anyone shed some light on the subject? I am worried that a lower resistance than an expected 14 Ohm is a sign the coil is about to go. As a side note - does anyone have any ideas on how to remove a stuck heating element? I tried nearly everything in my arsenal including a 600 ft-lb impact wrench - that element is really stuck in there. Thanks, Anton
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| Posted: Mon Mar 22nd, 2010 02:48 pm |
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2nd Post |
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uruiamme Member
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PB Blaster and see my previous thread about removal of difficult elements. http://www.thetankatwaterheaterrescue.com/forums/forum3/2586.html I prefer a good wrench and a huge cheater bar for more control.
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| Posted: Tue Mar 23rd, 2010 06:18 pm |
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3rd Post |
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eleent Member 
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Hello: Less resistance to ground in the lower element would indicate a leak in the sheath. There used to be a trick called "worrying". It was to turn something back and forth repeatedly to wear down the resistance, whether it was damaged threads, or rust. So, try tightening the element a bit, then loosen. Go back and forth. Try tapping on the breaker bar with a hammer, both tightening and loosening. The threads will let go  Yours, Larry
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| Posted: Tue Mar 23rd, 2010 06:30 pm |
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4th Post |
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anven Member
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I definitely see your point with the leak in the sheath. Will test resitance to ground/tank later tongiht. So far I have only probed between the two screw terminals. I also ordered a 1.5 inch socket - hopefully it will work better than the 7 dollar element pipe wrench. That thing is a piece of junk and just keeps slipping. Thanks for advice. Anton
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| Posted: Sat Mar 27th, 2010 02:26 pm |
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5th Post |
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energyexpert Member
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7.5 ohms is the expected resistance of two 3800 watt elements (@ 240 volts) in parallel. Puzzling. David
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| Posted: Sun Mar 28th, 2010 03:17 pm |
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6th Post |
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anven Member
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Yep - puzzling is a good way to describe it. I also recently discovered that the resitance fluctuates with temperature. When water is hot, I get 8.6 Ohm. Anton
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| Posted: Sun Mar 28th, 2010 04:50 pm |
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7th Post |
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eleent Member
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Hello: Did you try measuring resistance to ground? It should be infinite. Check between each terminal screw and ground. If you get any reading at all in the highest range, (ohms times 1000) the element is failing. I'd almost bet this will shed light on the problem  Yours, Larry
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| Posted: Mon Mar 29th, 2010 01:40 pm |
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8th Post |
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anven Member
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Yep - checked that. no connectivity to ground/case.
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