Finding Bad Element


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Old 12-30-05, 03:10 PM
J
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Finding Bad Element

I have two 50 gal State electric water hearters connected in series with a continuously circulating hot water loop. I suspect at least one of the elements has gone bad. Is there a simple procedure where I can identify which element it might be, and can this be done without draining the entire system? The downstream tank seems to feel slightly cooler than the upstream one but I am not sure.
 
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Old 12-31-05, 07:52 AM
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It could be an element, or it could be a thermostat. There is no need to drain ANYTHING until you know exactly which.

Start by shutting off the power to both WH's. Remove the thermostat covers. Test for power getting to the WH by turning the power back on and CAREFULLY check the voltage across the 2 top screws of the upper thermostat. If you don't have 230 volts, the problem is the incoming power. Check the breakers.

Next, check the elements for continuity. Turn the power off and disconnect both wires from each element, one element at a time. Check, with an ohmeter, for continuity across the screws of the thermostats. A good element will read something like 100 to 1,000 ohms. A bad element will read infinity.

If the power is good and all 4 elements test good, you probably have a bad thermostat. Since the WH's are in series, and the upstream WH is hot, it is working. You COULD reroute the water lines to take the downstream WH out of the system and see if it gets colder, but I wouldn't unless the supply line to it are leaking. I would simply replace BOTH thermostats in the downstream WH.
 
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Old 12-31-05, 12:55 PM
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Thank you Lefty. The procedure you outlined identified the lower element in the downstream heater as the bad element very quickly and easily. It had very high resitivity while the upper element had very little resistivity. I plan to get a new element on Monday as it appears that even HomeDepot is closed at this time on New Years Eve.

Do you have any tips or tricks I should employ in replacing the element? It appears that I drain the heater, disconnect the leads, and then just unscrew the element and replace it with the new one. The worst part appears to be the draining.

Thanks again for all your help.
 
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Old 12-31-05, 01:41 PM
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You've got the procedure -- turn off the power, drain the WH, unscrew the old element, screw in the new one, and FILL THE WH before you turn the power back on.

Now, a couple of tips.

Connect the hose and get it stretched out, then open the drain valve BEFORE you shut the water to the WH off. The pressure will help get things flowing.

A standard WH element wrench will work fine for installing the new element, but it may not be enough for getting the old element out. I use a 1/2" drive 1-1/2" socket and a breaker bar for that.
 
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Old 01-03-06, 06:58 AM
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Just a note to say many thanks, Lefty! New element is in, everything working fine. You and your associates on this site are great to take the time to advise and guide all of us want-to-be handimen. Thanks so much.
 
 

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