electric water heater headache

[tcl]

6-year old MayTag electric water heater - 50 gallon, dual element

- Model HE2950T. About two weeks ago, I had noticed that the hot water was way too hot. Didn't do anything. One week ago, the high temperature breaker on the upper thermostat started tripping. Once I reset the breaker button, it trips again a day later. The temperature setting on both the upper and lower thermostats is in the middle of the range.

Googled online and found some info on diagnose the problem.

Here was what I did. Fist I flip the main circuit breaker to cut off electric power to the water heater. Open both upper and lower access panels on the heater

1) removed one of the wire connecting to the heating element and then tested the resistance in between the two probes. My multi-meter read 10 ohms on both heating elements. So I concluded that the heating elements are good. 2) I measured the resistance in between the two probes (the two bolts where wires were connected) on the lower thermostat, and it read zero. So I concluded that the lower thermostat is good. 3) I did not know how to test the upper thermostat for there are so many probes...

Anyway, since there only a few things that could go wrong, and I have eliminated both of the heating elements, the lower thermostat, then I figure the upper thermostat must be the culprit. A replacement thermostat from Maytag costs $79.95. I am not ready to spend so much money on a thermostat... I found this thermostat online

Lowes does sell it for $12.98. contacted waterheaterparts.com to ask if the thermostat can be used on my heater. They told me that their product is rather "universal" for electric water heaters with dual heating elements and are wired for non-simultaneous operations. Well I know my model has two heating elements, but I can't tell if it is wired for "non-simultaneous" opeartions. Neither could they.

So I went to Lowes (I bought the Maytag there five years ago) and asked for the product. The guy at Lowes told me that they no longer sell Maytag water heaters. They now sell Whirlpool water heaters, and that since they sell this thermostat, it could be used as a replacement for Whirlpool electric water heaters. But he did not think it could be used on my Maytag water heater. he said something like there are some sort of internal "calibrations" specific to each brand of water heaters, and I can't simply use some other thermostats as replacement.

Now I am confused. A thermostat senses the water temperature. And when the water temperature is below a threshold you set, it sends a signal to the heating element to heat up the water. When the temperature in the water goes above the threshold, it sends a signal to stop the element from further heating the water. What kind of "internal "calibrations" are needed for different brands of electric water heaters?

So I am wonder if anyone can shed some light as to what replacement thermostat I could use for my water heater. The Maytag customer support is terrible. The number printed on the user manual is no longer the right number.

Thanks for any help,

Ted

[Mark]

Good start...

I assume this is a 220 Volt system...

in which case you should also check the heating elements for shorts to ground...

Use your ohmmeter to check for an undesried connection from each heating element input terminal the the grounded metal housing... that would be an undesried short and would cause the element to draw current all the time.

BE SURE THE POWER IS OFF WHEN DOING THESE TESTS

Mark

[tcl]

Thanks for the advice.. The upper thermostat on my electric water heater looks exactly like this one

online.

Since all those thermostats out there are pretty much generic type. And such generic thermostats are so much cheaper than the ones sold by the manufacturer. I dont really mind to replace both the upper and the lowe thermostats just to be safe.

The question is, can I do that (i.e. replace both thermostats by generic ones)? Again one vender told me that the thermostats they sell (American Water Heater brand) for dual heating elements (upper thermostst w/ high temp limit) is specifically wired for non-simultaneous operations. How do I know it is good as a replacement for my water heater? Do I have to contact Maytag and ask if my water heater is wired for non-simultaneous operations. Again, trying to call Maytag customer service is a pain...

If replecement thermostats are so specific for each brand, why there are so many generic, universal thermostats for electric watyer heaters?

Ted

[gfretwell]

You can eliminate the bottom one by disconnecting the wire to the bottom element and see if it still overheats, If so the top is bad. If not the bottom is bad.

[tcl]

Thanks, definitely will try this test over the weekend. But that does not answer my question. Can I simply go out and buy a generic thermostat instead of getting the factory thermostat from Maytag, which is four to six times more expensive.

[George E. Cawthon]

Yes. A cost of $80 for a thermostat is outrageous. Your Maytag is probably identical to Lowe's Whirlpools.

You talked to people that know nothing and you got nonsense. If you google water heaters online you will find all sorts of information including test procedures. Many plumbing and electric shops also have leaflets that show you how to check the heaters and the thermostats.

If you listen to people who know nothing, you will likely come away with nonsense because most know-nothings can't say, "I don't know." There are no internal calibrations, what the guy probably meant is the wiring may be different.

As long as it fits, it is likely to work. If you find a thermostat that looks like yours with identical connection points, it will probably work.

[Ashton Crusher]

Since your heater is 6 years old it's entirely possible neither of your thermostats is bad but that the bottom has become so caked with calcium deposits that water can hardly get to that area anymore. I have a 6 year old (Whirlpool I think) heater and it has burned out two bottom heating elements due to calcium buildup. When the calcium builds up the element gets too hot because the water can't easily get to it and circulate, then the element starts to overheat and eventually it will burn thru and short out thru the water tripping the breaker.

Mine was also a non-simultaneous set up, I think almost all of them are if they are of any decent size because it would draw a lot of current to run them both at the same time and its not really necessary for home use. I don't know but I suspect simultaneous ones would be used in commercial buildings needing a continuous supply of hot water over long time periods.

[gfretwell]

As long as you understand what is going on any thermostat rated for the element size will work. The top one is a 2 way switch, the bottom is a single way (on/off) The top heats up, switches power to the bottom, when the bottom heats up it turns off. If either stick "on" the water overheats and the top overtemp trips.

[trader4]

And how does that explain that he's been getting super hot water? His problem isn't burned out elements, it's water that's too hot.

[Don Young]

At one time the thermostats only opened one leg of the power so when an element burned thru the housing the current would flow from the unswitched leg thru the water to the tank or piping and thus to the ground. This would continue to slowly heat the water and would overheat the heater if little or no hot water was being used.

The symptoms would be a combination of inadequate hot water when being used regularly and overheating when not being used.

Don Young