Freezer Got Really Hot!!, Pictures

My wife told me our freezer didn't seem to be keeping things very cold but dismissed it saying the door might have been left open by one of the kids. A day later the freezer really didn't seem to get any colder so we emptied it out. In the bottom left corner on the interior of the freezer there was a spot about the size of a quarter that looks like it got hot. Kind of like if you hold a torch to the back side of a piece of painted steel. I took that panel off and it looks like a section of the tubing melted/blew out. What exactly happened here?

Thanks
a273696.jpg

a273697.jpg

a273698.jpg
 
Looks like the remnants of a fire running hot enough to melt copper and aluminum. Looks like somebody took an Acetylene torch and blasted it for a bit. Failure mechanism? I don't see one. Freon gas isn't combustible, ref oil would have to get up around 400F range. What I see doesn't make sense.
 
Those freezers normally have some sort of auto-defrost mechanism, but I don't know enough about them to know where that might be.

If you find out any answers, please let us know.
 
Is that a defrost heater perhaps. If it were a freon line blown where is the oil that would have come out, and what could have burned thru the line. Again it looks like a heat strip.
 
I never looked into, nor studied auto defrost systems. Just assume it's like a room air conditioner/heat pump...you just reverse the direction of the "gas
cycle" reversing the position of the evaporator coil and condenser coil. To do that you need a switch and wires to control it. I see neither......I see the
thermostat, know not where it was located, but by looking at it, it is not your smoking gun!
 
Very well could be how auto defrost is accomplished. Turn off the compressor, and turn on a heat strip to effect the defrost function leaving the air
circulating fan running. Much cheaper than what ACs do. Now, where is the strip and where are the wires to make it work? Will have another look at
the picture. An electrical short could do this if adequate current were available.
 
Looks like the orange on the left and black on the right are your circuit for a strip heater. I don't see much POW with what looks like a 20 AWG wire and 120V.....VA at 500 W (5 amps), maybe 1000 before the wire melted. Course fusing current on 20 AWG copper (per powerstream.com) is 58 amps x 120v would equal enough power to do what we see before the wire melted.

So, I'll buy into the strip heater is the villian. Problem with that assumption is being a strip heater you would expect a linear strip of resistive material. It's not like a transformer winding where the heat is centralized in one spot. Course you could have a corroded connection where the wire and the resistive heater are joined and that spot is where it would occur. Corrosion sets in, resistance increases and is concentrated at that point. Time lapse and a thermal runaway situation occurs and the connection burns into.

That very well makes sense and could be your smoking gun. I hope you didn't lose any food over the deal.

Geez, I don't have to work crossword puzzles with breakfast this morning. I have had my mental exercise.....keepasAlzheimers at bay.
 
I'm going with a shorted defrost element.

Will the compressor run and the evap get cold if you plug it in?

If the compressor doesn't run, chances are the defrost timer is stuck in the defrost mode. That would stop the compressor and explain why the heater melted, it stayed on too long.

As long as the evap coil is not damaged, and it doesn't appear to be, a defrost timer and defrost heater should fix it. Look up a parts list, see if it has a defrost timer. It may have a circuit board instead.
 
(quoted from post at 09:19:11 07/16/18) I'm going with a shorted defrost element.

Will the compressor run and the evap get cold if you plug it in?

If the compressor doesn't run, chances are the defrost timer is stuck in the defrost mode. That would stop the compressor and explain why the heater melted, it stayed on too long.

As long as the evap coil is not damaged, and it doesn't appear to be, a defrost timer and defrost heater should fix it. Look up a parts list, see if it has a defrost timer. It may have a circuit board instead.

BINGO!!
This is likely what happened. Defrost timer did not turn off.
The heater is just like the heating element in an electric oven.
Except the metals used are not as exotic since it is a low heat app.
The outside metal tube contains a ceramic type of material and the coiled wire element centered inside the tube. If the element gets to hot, it will blow like a volcano. If the element is also in a bend or u-bend it will blow a hole where it is bent before it does so in a straight section.
 
"it looks like a section of the tubing melted/blew out"

The actual part burned through is the defrost heater, more or less basically a small oven element.

Defrost is timed, even if timer stuck, there's a thermostat that opens and ends defrost when coil temp get to perhaps 40? to 60? and doesn't close again 'til area is freezing.

Thermostat is the black part at the upper left connected to the orange wire.

My GUESS would be that the heating element simply failed internally and burned through, much like an oven element occasionally does.

Did it burn through the refrigerant line near it and release the refrigerant?

If NOT, the element can be replaced and the thermostat and timer replaced and the unit should work.

Below is a link to a vid of replacing a similar defrost heater.
Replace defrost heater
 
Attached is a diagram of a frige wiring system. It?s for side by side but principle is same.

Defrost timer switches between run and defrost. Defrost is simply a couple of series heaters mounted behind or under the evaporator coils. Timer turns them on approximately every 8 hours of compressor run time. There is a hi-limit thermostat in series with the heaters to prevent over heating.

The heaters I?ve seen are a resistance coil enclosed in a glass tube with plug connections at each end.

In your pictures the orange to white wire on left and white to black wire on right are the heater connections. There would be a connecting wire between the two heaters.

It appears to me that two metal straps hold the bottom heater element to the coil. My guess is that the left side bottom connection on the heater element developed resistance over time and created a hot spot. I had that happen to my frige at home and burned the wire off the the heater connection. I was able to clean and repair the connection and so far so good. You may need a new heater element
a273703.jpg
 
Hello Christopher S,

Looks like the defrost heater failed. If the evaporator tubing got burner through, all the refrigerant went out, so it is toast! However if the evaporator is intact,
It may be salvageable. In the right side of the second picture is the defrost timer. The fail with the heater on usually. The two blue and black wires are the 120 V clock-timer wires. The other two control the defrost element-s.
If it has refrigerant still in it, replacing the timer and the defrost element should get you back running,

Guido.
 
Follow the wires from that timer that is hanging down. You will find a heater at the bottom of the coils that the timer turns on after a set time, either every so many days, or so many hours of run time, to defrost the coils. That heater is burned out, possibly because of a bad timer, but there should be a little round thermostat in there to shut the heater off once it gets to a certain temperature in the compartment. I suggest replacing both the heating element and the timer. If the rest of the fridge is staying cool you probably have not lost freon. If you have lost freon, it is probably better to buy a new refrigerator, because the needed parts plus having someone recharge it will be about a third the price of a new fridge, and the new one will cost a lot less to run.

In case you are wondering, yes, I used to work repairing appliances in a Whirlpools shop.
 
Hello Texasmark1,

What you described is a hot gas defrost system. Totally separate piping from the refrigeration cycle. Window A/C units? No need for a defrost system, as it operates at a higher pressue-temp. ASSUME = A$$ U AND ME,

Guido.
 
Defroster coil burnt out. I have the exact same freezer design at our plant, mine being a Frigidaire.

The coil is available but shop around. I got mine from a guy on Ebay. Before I would do that however I would plug it back in and see if the compressor will still cool it. The refrigerant runs through aluminum tubes and that coil that failed is right under them. If it burned a hole in the tube it's toast.

For insurance I would swap out the thermostat while you are in there. You will likely have close to $100 in parts for an older freezer but even if you get another one used you might have the same problem later.

I struggled with this for a bit and looked at new ones as well as used and decided that the new ones are junky so in the end there wasn't that much downside to repairing the old one. Ours runs just fine now so it was a good experience.

If you need more details and or help message back.
 
Do not try to salvage that. Dad had theirs repaired, YA Right, burnt their house to the ground a couple days later
 
Thank You guys for your replies, it really is amazing the wealth of knowledge you all bring to the table. I took another look at it last night and there was a pin hole in the tubing right above the heater coil. So I would say all the refrigerant has been left out. To the scrap pile this one goes.
 
Bottom picture clearly shows the heat coil burnt up.. the little collar is looped around the heating element and holds it to the freon coils. Very common failure, but the burnt spot is unusual. If the freon coils are undamaged, and did not leak, its a matter of replacing the heating element and maybe the defrost timer if damaged.

. You might have to unplug the heat coil first, plug the fridge back in, and see if the freon coils get cold.. If they do, just order a heating element, and then cycle the timer to see if the compressor cuts off and the coil gets hot.. If so,, close it up and all is good. Note that in the original design they try to keep all of the dripping water off the connections on the heating element as over time, these connection will corrode, and get hot, and burn up and ... ...........



If the freon coils no longer cool, time to replace it, but make sure the defrost time is not stuck on,as it turns off the comrpessor during the defrost cycle..
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top