Electric Water Heater Tripped for No Reason - Why?

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This morning was the coldest day of the year in the Washington DC area - a bone-chilling 21 degrees F. I stepped into my shower and lo and behold - no hot water! I scurried to the basement, checked the main circuit breaker and the water heater/deep well pump breaker and everything was on - they did not trip.
I went to the water heater - a Bradford White Hydrojet that is less than 3 years old - opened the upper panel, pushed the red reset button, heard it click, and waited a few minutes. Later, I felt the copper tube on top warming up again and when I checked the water faucets, the water was starting to get warm. I had to leave for work so I didn't have a chance to see if it would trip again. I'm now in the office for 3 hours and the wife has not called, so I am assuming things are back to normal.
I have done a fair amount of reading on the subject but, given the relatively young age of this unit, I don't believe there is anything wrong with the thermostats or the heating elements.
So my question is - is this just a fluke, an act of God, a one-time random event that may never happen again? What could have caused it to trip without the main breaker going off? Could the cold weather have anything to do with it? What about the fact that our water source is a deep well pump?
I guess I'm just looking for a rational explanation, so that I will have peace of mind if the heater switch does not trip again. Thanks for any insights, tips, comments, etc.
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On 16 Dec 2004 05:16:26 -0800, snipped-for-privacy@yahoo.com wrote:

imho: Sometimes breakers just go bad. You can verify this with a clamp on amp meter. Which should only be done by safely trained professionals.
later,
tom @ www.FindMeShelter.com
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snipped-for-privacy@intertainia.com wrote:

Tom, it appears you missed the entire point of the OPs message, the "red button" is a THERMAL overload, not an overcurrent one. While your statement about "breakers" is valid, the only part about it which is pertinent is that if the OP doesn't have the skills and knowledge to work on and/or change out a water heater thermostat then he SHOULD call in a professional.
The "most likely" cause of it tripping is that either the upper or lower thermostat got "sticky" and didn't open, and the temperature in the heater rose to the point where the thermal overload tripped. I've never seen one "trip by itself" with water in the normal temperature range.(I'm assuming that since you mentioned opening the "upper panel", there's a lower one too, so there's two thermostats on your water heater.
Chances are that even if the sticky operating thermostat reopened, it'll stick again in the near future. (Things which go away by themselves usually come back by themselves, y'know. <G>) The safest thing to do is to replace the sticking if you know enough to be able to circuit trace and catch which one is stuck, otherwise change out BOTH thermostats, they're cheap enough.
You may very well be able to get a replacement thermostat at no cost under warranty if you know which one it is. But, since they're relatively cheap and available at Home Cheepo, waiting for the factory to exchange one under warranty isn't much of an option.
HTH, and Happy Holidays,
Jeff
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Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)
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I can back-up Jeff's advice.
In the first house I owned, I had exactly the same experience with a water heater that was < 2 years old. Temp safety switch tripped for "no reason", I reset it, tripped again a couple weeks later, then it became more frequent. Along the way, I noticed that the hot water was intermittently a lot hotter than normal.
Flipped a coin and decided to replace the upper thermostat which did not fix it, so I replaced the lower one which *did* fix it. Like Jeff said, they're cheap and if I have the same experience again I'll just replace both.
Eric Law
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EL wrote:

I wouldn't have flipped a coin... I would have gone for the lower stat, on the theory that with typical household hot water usage vs time the heater is probably cycling on that one most of the time and only flipping the upper stat at those times when so much hot water is drawn continuously that that the water at the upper stat gets cool enough to flip it on. That would auger for the lower stat being the one to "wear out" first, huh?
I've got a neon pilot lamp hooked to the upper element on mine, and while I'm near the water heater frequently ('Cause it's in my basement home workshop.) The only time I can recall seeing it lit was near the end of one of our daughter's nerve wrackingly long showers, just before I reached over and shut off the heater's water inlet valve. <G>
Happy Holidays,
jeff
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Jeffry Wisnia

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I think the lower one runs until it's satisfied, and then the upper one. Or is it the other way around? Ah, well. Rip em both out.
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Christopher A. Young
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On Thu, 16 Dec 2004 10:19:12 -0500, Jeff Wisnia

OH! I thought I DID miss what he said. Thought it was another breaker going bad story. Atleast I got the suggestion to have it looked at by 'trained professionals' part right.
:-P

later,
tom @ www.CarFleaMarket.com
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On Fri, 17 Dec 2004 21:57:35 -0500, snipped-for-privacy@intertainia.com wrote:

Good Grief !!!! You dont need a friggin "professional", unless you like to throw monye away. Replace the elements if you got money to waste, and you'll still be ahead.
Mark
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On Thu, 16 Dec 2004 10:19:12 -0500, Jeff Wisnia

I would tend to disagree that the heater overheated. The OP said the water was cold in the shower in the morning. If the water was overheated, it would still be hot, or fairly warm. I can shut off the power to my water heater and 24 hours later still have relatively hot water (assuming someone did not drain the tank).
Since the OP has a well, I'd check the elements. Only 3 year old tank does not mean anything in a rural area. Sure, the tank itself should be in good shape. BUT........
Lightning can be nasty in rural areas because of the long runs of overhead wires and few ground points along the way. A lightning strike last summer may have blown a tiny pin hole in one of the elements and discharged into the water. I have fixed several of these, and its more common that you would believe.
You could also have a high acidic water that ate a hole in an element.
You could have a combination of both of these that finally drew enough current to go POP.
Pull the elements and thoroughly inspect them. Wipe them down with one of those green pot scrubbers (scotch pad), and you should see any pin holes or cracks. Usually they stay wet after you dry the rest of the element.
If thats too much effort, either learn to live with the hot water cutting off more and more in the future, or hope and pray that that someone broke into your home while you were away, and did it just to trip that red button. By the way, if your income is at or near any of those political idiots in DC, just buy a new water heater and donate the old one to charity so some needy person can fix it.
21deg.... Geeshhhhhh, I hope the shrub freezes, shrivels, and wilts away !!!!
Mark
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On Fri, 17 Dec 2004 22:35:06 -0600, snipped-for-privacy@UNLISTED.com wrote:

The button could have been tripped for a day or longer before the tank ran out of hot water. Even overheated water cools or gets used up eventually.
Steve B.
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Yeah, it could have been a day or longer, but wouldn't overheated water be colored RED?
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snipped-for-privacy@UNLISTED.com wrote:

It wasn't a CURRENT overload that popped.

I won't disagree that the elements could *also* be bad, but "how the F" will that trip a thermal breaker?
If you've ever taken a thermal breaker apart you know that it consists of a disk of bimetal formed into a shallow "dish". When the tank shell reaches the "overtemperature" point the dish inverts (with a snap) and opens a set of contacts which break the line voltage feeding everything else in the water heater.
Now, tell us how a damaged element will cause the water to heat up enough to pop the thermal overload? And even if it in some arcane way does so, why doesn't the operating thermostat open first and thus keep the water from getting hot enough to pop the thermal overload?
I repeat, it has to be caused by a stuck operating thermostat, most likely the lower one.
Happy Holidays,
Jeff
(W1BSV + Brass Rat '57 EE)
"As long as there are final exams, there will be prayer in public schools"
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On Sat, 18 Dec 2004 13:46:50 -0500, Jeff Wisnia

Some bottom thermostat setups only switch one side of the 220 going to the element. If the element suffers a failure that allows current leakage but isnt catastropic to the element you have a 110v potential on one side and a nice ground path through the defect/water on the other so the element can continue to heat at 110v with thermostat off. Eventually it could get hot enough to pop the overheat on the top thermostat
It would seem that the odds of this happening would be somewhere around the odds of winning powerball but it is possible.
Steve B.
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Steve B. wrote:

You know, I thought of that, which is why I said "arcane", but I've never heard tell of that kind of failure before. And you are correct about the possibility that a single pole lower thermostat could let that sort of fault keep heating the water regardless of the state of that thermostat.
But I'm not up to visualizing what kind of mechanical/corrosion failure would permit that sort of current flow; I'm kinda out of my element here. <G>
The OP's problem *might* not be with the control thermostat, but it's darned well the way to bet.
Happy Holidays,
Jeff
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Jeffry Wisnia

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<<Water heater tripped for no reason... >>
It tripped for a reason, you simply haven't found the problem yet. Applying simple logic, there could be a defect in the overtemperature control, since the reset brought it back on line. Check it on a fairly frequent schedule for a repeat of the problem and replace the unit if the problem persists. We're assuming here that the water heater temperature controlling system itself hasn't gone haywire. Indications of that might be an unusually high hot water temperature, say 180 F or so. Good luck.
Joe
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Thanks for all the great advice. The unit has not tripped again for the last 48 hours after I pushed the red reset button. However, I did notice that the water is hotter than what it used to be. I adjusted both thermostats to the lowest level (120 degrees F - the factory settings) but the water is still much hotter than before. So I have made a decision to replace both thermostats on my own.
The water heater is a Bradford White Hydrojet Model No. MI65R6DS13, 65 gallon tank, double element. However, I've searched around the internet and virtually all of the aftermarket thermostats around are generic, so how do I know which thermostat will work with my heater? Are all upper and lower 240 volt generic thermostats for double element electric heaters interchangeable? The brands I found are American Water (Lowe's) and Apcom (Home Depot) but there is no cross reference chart around that tells me which part fits which model.
I could shut the house down, take the existing thermostats off and take then to the hardware store as samples, but I want to avoid doing this if I can.
I would thus appreciate any assistance/advice in this regard. Thanks and best regards.
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posted for all of us....

Why not call up the manufacturer & have them sent to you?
--
Tekkie

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On 17 Dec 2004 05:15:51 -0800, snipped-for-privacy@yahoo.com wrote:

Theres no need to "shut the house down". Simply turn off the power to the water heater, remove the thermostats and go to the hardware store and get two new ones.
Steve B.
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Had the same problem in a rental unit, coincidentally with a three year old Bradford-White; mine only has a single element.
The tenant reported no hot water, so I went over and pushed the reset. Same thing happened the next day, so I pushed the reset and it was fine for a month. When it happened again, it lasted two weeks. No rhyme or reason or pattern or logical explanation; it just happened.
Finally got tired of fooling with it and replaced the thermostat. That was a month ago and(knocking on wood with fingers crossed), no problem since.
Thermostats are cheap and it's not worth the frustration to try to troubleshoot the problem. If it happens again, just replace the 'stat.
John
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This problem has defied all explanation.
I have replaced both thermostats - the upper and the lower - with the exact same model that the unit had - and the red button tripped again! So by process of elimination, I have to replace the elements now. I have no problem doing both but I've never done this before. Do I just unscrew these things or do I have to drain the tank? Any instructions would be appreciated. Thanks once again.
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