My Kenmore (Sears?) electric water heater stops to works (not more hot
water), but the light is on.
I supposed it is the thermostat.
I removed the 2 front panels from the boiler and check with ohmmeter
the 2 resistors (elements, I think 3300 watts each) and the 2
The resistor on top shows infinite resistance (I suppose is broken),
but the second one shows continuity.
When I measured voltage with voltmeter, the resistor on the top (which
is broken) has 240v, but the resistor down (with continuity) shows
I did suppose one of the thermostats is not more working.
There is a "Reset" red button, I did push it but nothing. What is the
purpose for this button?
The labels on 2 thermostats are "7135" (on top - many wires) and
"7059" (on down - 2 wires).
Following the circuits, I noticed the thermostat and resistor on down
(2 wires) is supplied with voltage from the box (thermostat) on top
May I put some wire in direct to provide voltage to the resistor on
And another question: What happen if the resistor on to is broken? May
I live it like this? (supposing the resistor on down will work).
Thanks for your suggestion.
You have diagnosed it correctly, from a "cold start" the upper heating
element runs until the water at the top of the tank reaches the setpoint
of the upper thermostat at which point power is removed from the upper
heating element and directed down to the lower heating element through
the lower thermostat. That element remains powered up until the water at
the bottom of the tank reaches the lower thermostat's setpoint at which
time it opens and no power is consumed until the water in the tank cools
through heat loss or someone uses hot water.
You won't kill anyone if you rewire things so that power only goes to
the lower thermostat and thence to the lower heater, and you will get
hot water to use, but you probably won't pleased with the "recovery
rate" for hot water.
If you decide to do that, please disconnect and safely cap off the leads
going to the upper element just in case that elemen is rusted through
its outer sheath.
Running on just the lower element and thermostat may just get you by
until you can fix things properly, but it's no way to leave things now.
As someone already said, replace the upper heating element, they are
really inexpensive. And do spring a few bucks for the "socket wrench"
sold specifically for grabbing the big hex on those elements. It'll make
you job much easier.
The thermostat has lots of screws, and the heating element is usually
below it. You're calling it a resistor because you have the schematic
and it uses the symbol for a resistor??
The heating element has only two or three screws. I have Kenmore
too, but I think all the brands are alike, insofar as, if the heating
element has two elements in one, it will have three screws, and a
jumper was originally provided so that one could connect two of them
to one wire, and the third screw to the other wire, so that both ran
at once. Then one is supposed to note this on the spec plate that is
on the outside of the water heater.
You understand why, right?
Well, you noted that the red light was on. That only goes on when the
top thermostat is closed, which should cause the top element to make
heat, but you've shown that it is broken.
When the top thermostat is closed, the bottom thermostat is always
open on Kenmore and most wh's. So that's why there is no voltage on
the bottom resistor/element.
The thermostat is connected to but separate from the heating element.
When the water is hot enough at the thermostat, the thermostat will
open. If the water gets too hot, because one or the other thermostat
is broken, the heat limit switch in the thermostat opens. The red
button is to reset it. It won't reset itself, so if the button needs
pushing, you have to push it or the element just below it won't make
Two wires, but more than two screws, right?
Yes but don't do that. I think a new heating element is about 20 or
When the top element heats the water at the top to the right
temperature, the thermostat will turn the top element off, turn the
red light off, and turn the electricity on to the bottom
It doesn't get hot now, becuase the top heating element is broken.
No it won't work, as I just said above. The bottom won't work until
the top heater warms the water at the top enough. And it's not.
So, unless we're confused, turn the WH off at the breaker, and replace
the element. Use 1) or 2)
1) Drain the tank enough to lower the water level below the top
element** You have to turn off the input water, and open the drain
valve, and estimate how much water is coming out. Maybe you need to
run a garden hose from the drain to the sump or somewhere. Although
if you are only draining the top part, you could run the hose to the
basement sink (or toilet I suppose) Either will be lower than the top
2) **There is also a way to not drain the tank and all which might be
better since some times one can't shut the drain after he opens it.
In that case the input water is turned off, the hot or cold*** (I
forget which) faucet that is lowest in the house should be opened wide
and let to run until no more water comes out. --- This whole method
only works if you already have the new element. --- When no more
water comes out, unscrew the old element, then pull it out and put in
the new one as quick as you can. Maybe 3 or 4 seconds. When I did
it, only a couple tablespoons of water came out. (Because the partial
vacuum at the top of the tank holds the water in.)
Then tighten the heating element, close the water faucet, turn on the
water to the wh, go to the water faucet and run the water until all
the air comes out and give the tank time for the water to fill it and
cover the new element. If you run the water heater with an element
exposed to air, it will burn out, even though you just replaced it.
Then connect the wires, and when you are sure the wh is full, you can
turn the electricity back on.
***I guess if you are opening the cold, you have to turn off the water
to the whole house, or the water will never stop running. So that's
why I thought it was the hot, but it's been 20 years and I don't
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