Can you help troubleshoot my hot water/high electricity bill issue?

[hj]

1. I NEVER test an element with an ohmeter
2. You should ALWAYS remove the wires from the element if you are testing with an ohmeter, which should eliminate any problem with corrosion, since you would NOT test on the screw.

[Thatguy]

1. I NEVER test an element with an ohmeter
2. You should ALWAYS remove the wires from the element if you are testing with an ohmeter, which should eliminate any problem with corrosion, since you would NOT test on the screw.

After prepping the contact points with fine sandpaper I use ohmmeters because of zero shock risk, but they do have their limitations.

[ballvalve]

I have elements with holes in them that apparently leaked the electricity to ground rather than heated the water. Just not enough to trip a breaker. Go figure.

[Thatguy]

I have elements with holes in them that apparently leaked the electricity to ground rather than heated the water. Just not enough to trip a breaker. Go figure.

So there was current flow in the pipes to ground. 10' of half-inch ID copper pipe has a resistance of . . .I forgot. When this wine wears off I can probably tell you.

Or not.

[hj]

quote; I have elements with holes in them that apparently leaked the electricity to ground rather than heated the water.

When that happens one part of the element operates at 120 v. If it is the WRONG half, then it bypasses the thermostat and overheats the water until the "ECO" pops out. It is a COMMON problem, but is easily detected with an ammeter. WHich is why I use that instead of an ohmeter.

[ballvalve]

I use an ammeter too. Just installed 2 new 4500w elements. [both operate together]

1 element; 17.8 amps on one wire, 19.9 on the other

1; 18.5 a on one side, 20 on the other.

Seems they should read the same on each wire. Never seem to. Whats up?

[Thatguy]

100x20/17.8= 112 % so the tolerance on the hot resistance value for elements is maybe (112 - 100)/2 = +/- 6 %, assuming this small sample size of 4 is representative of all 4500 W elements. Probably the actual tolerance is quite a bit wider than 6 %.

Close enough for guvmint wuk!

And the cold [or hot] resistance values for "identical" brand new incand. bulbs is probably all over the map but the hot values may have tighter tolerance limits.

Not much precision required in either case and precision costs money.

http://statpages.org/tolintvl.html

The likelihood that you would get two consecutive element readings identical to within 1 % or 0.1 % is probably close to zero.

And this book
http://www.probability.ca/sbl/
says you're more likely to die in a car accident on your way to buy a lottery ticket than you are of winning that lottery.