I have a problem with my electric water heater, which is 66 gallons,
Sears brand, 13 years old.
We bought this house about six months ago. Yesterday, without any
previous symptoms, I found the water from the heater very hot -
steaming. Since we were in a hurry to go out, I just switched the
heater's circuit breaker on the main board OFF. I thought the
thermostat might have gone bad and decided to replace it by myself
Today morning, I switched the circuit breaker back ON to get some hot
water (generally I don't switch off the heater at all). After an hour
or so, since I did not get any hot water, I inspected everything and
found that the circuit breaker of the water heater on the main board
I searched google.groups and found a lot of information regarding this
- with possible causes, (1) a stuck thermostat OR (2) bad heating
To experiment, I turned the bottom thermostat all the way to the
lowest point. Put the upper thermostat at a medium level and switched
the circuit breaker back on. Within about 5 minutes the circuit
breaker tripped again. I tried the same experiment with the upper
thermostat with similar results.
So here are my questions. I think either the thermostat(s) or the
heating element(s) had gone bad.
(1) Should I get an electrician to repair the heater - replace the
thermostats and/or the elements OR
(2) Considering the age of the heater (and the previous owner was not
good in maintaining it – she never drained it in a period of 5 years),
should I buy a new heater.
Thanks in advance for your time.
I assume from reading your post that you haven't yet put in that new
thermostat, unless you did it in the middle of the night "today".
The problem you describe would be a cinch for someone with the right test
equipment and understanding of "hot water heater electrics" to diagnose.
All it takes is an amprobe (current meter) and a voltmeter (if that's not
already combined with the amprobe.
Without test equipment you're likely to frustrate yourself stumblig around
"blind", which is what you'll be doing if you can't make voltage and
current measurements to track down the culprit.
The typical 220-240 volt hot water heater with two elements works this
From a "cold" start, current flows through the closed upper thermostat
contacts (and the overtemperature cutoff device) to energize the upper
Assuming nobody's pulling hot water from the heater:
When the water in the upper part of the tank reaches the upper
thermostat's set point temperature, that thermostat turns off the power to
the upper heating element and enegizes the input of the lower thermostat,
which will power the lower heating element until the water in the lower
part of the tank reaches the setpoint temperature of the lower thermostat.
Fom that point on, the lower thermostat will cycle on and off every once
in a while to keep the whole tankfull at a contant temperature.
When hot water is drawn from the heater:
It is taken from the top of the tank, and cold water enters at the bottom
of the tank, through a "dip tube" extending down to near the tank bottom
from the "cold" inlet fitting at the top.
The lower thermostat will close first, as the entering cold water cools
it, and will enegize the lower heater. If hot water continues to be drawn
off, the lower heater won't "keep up with it", and cooler water will reach
the upper thermostat, causing it to switch over to powering the upper
If water continues to be drawn it will take heat away faster than the
upper heater can keep up with and you "run out of hot water."
(End of narrative.)
I think your best bet is to bite the bullet and have a new hot water
heater installed, given the age of your unit.
Otherwise, if you don't have a friend who knows these things and has the
right test equipment, you are going to have to find a repairperson with
enough smarts and the right test equipment to properly diganse and fix the
problem without replacing more parts than are really needed. Sad to say,
those aren't the attributes of every plumber you might call. A qualified
person's laborcharges, plus the cost of the repair parts he supplies (at
"full retail" of course.) makes buying a new heater not such a bad thing
That said, if you happen to be near Zip 01890, I'd come over and give you
a hand gratis, just because...
Happy New Year,
Jeff Wisnia (W1BSV + Brass Rat '57 EE)
"If you can smile when things are going wrong, you've thought of someone
I think so too.
This is my reasoning: having both the water overheat _and_ the breaker
trip is suggestive that the OP has multiple faults in the heater, and
short of having an expert diagnose things, the OP may get himself
into real jackpot. Plumbing prices being what they are, hiring a plumber
to diagnose and repair the heater will probably cost nearly as much as a new
1) if the water overheated, the thermostat isn't tripping. So, you have
fairly good evidence that the T-stat is defective.
[At least you noticed this. In some cases (stuck OP valve (they get stuck
with age) and a non-return valve in the supply), a failed thermostat can lead
to a steam explosion.]
2) If the breaker trips, either something is wrong with an element, or the
thermostat is broken to the point of energizing both elements simultaneously,
or the breaker has gone defective too.
3) If both elements energize simultaneously, I would _expect_ the breaker
to trip faster than 5 minutes. Unless the double element current is only
a bit higher than the breaker.
4) It's fairly unusual for an element to draw more current than it should.
They usually simply go "open". For an element to draw more current, I
would immediately suspect that the element coatings have delaminated, and
either the upper element has broken and fallen on the lower, or, something else
has fallen on the lower element (eg: a corroded-thru anode).
I personally would expend effort to diagnose the problem[s] before deciding
to junk the heater. I hate replacing things when I'm not exactly sure what's
In your case, I'd suggest:
Energize the unit again, and test for voltage on _both_ elements, using
a voltmeter or neon tester. If both elements are energized simultaneously,
you've identified the cause of the breaker trip - you already know the
thermostat is defective (because of the overheat), this rules out the elements
as a cause of the breaker trip.
If both elements energize simultaneously, replace the thermostat.
If the thing is still flakey, get a new tank, and return the T-stat.
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
Thanks a lot to everyone who responded to my question.
I bought a new water heater - not installed it yet.
Special thanks to Chris Lewis and Jeff Wisnia for their detailed
replies, which helped me to learn more about water heaters.
email@example.com (Chris Lewis) wrote in message
Check to see if the last owner kept the extended warranty up on the water
heater. Sears loves to call up every couple years and talk you into
extending the warranty on what you have purchased.
Plan B: Get a new one.
In 1980 my elec water heater died; I called Sears, they were out the next
day (door unlocked, I was at work) and replaced it, no problem. The only
problem was they signed me up unasked for the super duper extended warranty. I
called and cancelled it. What a rotten deal that would have been.
The unwarranted water heater is still going strong. The sulphur smell ended
after a year, after the anode rod burned through I guess.
I like your premise except the last part. Who has a more
efficient one? And how would you make one electric heater
more efficient than another. Efficiency usually refers to
converstion of one energy time to another such as
electricity to heat in this case. All electric water
heaters have the same efficiency--100 percent. Some are
better insulated but even a poorly insulated one can be
cheaply retofitted to save heat loss.
But, do those warranties transfer to a subsequent owner?
The OP said he bought the place 6 months ago..
Jeff Wisnia (W1BSV + Brass Rat '57 EE)
"If you can keep smiling when things go wrong, you've thought of someone to
place the blame on."
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