fridge repair

Any appliance repair experts out there? I have a bad defrost thermostat on a magic chef fridge. I was wondering if I can use a defrost thermostat off of a similar GE fridge. they work by opening and closing based on temperatu re so I dont see why they wouldnt be interchangeable. Any ideas?

Reply to
Jdog
Loading thread data ...

n a magic chef fridge. I was wondering if I can use a defrost thermostat of f of a similar GE fridge. they work by opening and closing based on tempera ture so I dont see why they wouldnt be interchangeable. Any ideas?

Any good appl;iance repair parts store should be able to cross-reference pa rts. The exact temperature setting might be stamped on the thermostat. Bu t, I would be skeptical of just blindly replacing one brand with another as you don't know exactly what the manufacturer considers the correct tempera ture for defrosting. Obviously the temp has to get above 32F, but one manu facturer might use a 40F thermostat, while another uses 45F to get the job done faster.

Reply to
hrhofmann

My brother and I know everything there is to know about appliance repair.

Sorry. That's one of the things my brother knows.

Reply to
micky

Jdog:

Yes you should be able to.

Be advised that a defrost thermostat is now officially called a DTS, or Defrost Termination Switch. That's because the operation of the device is more similar to that of a switch than that of a thermostat. A thermostat CONTROLS the temperature, trying to maintain it at a certain set point, whereas a switch doesn't, and DTS's don't do any controlling at all, so genetically, they're more closely related to switches than thermostats.

Also be aware that every different model of DTS actually has two temperature switching points. The DTS will typically open, thereby breaking the circuit to the defrost heater at a temperature between 32 to 45 degrees Fahrenheit, but then the DTS will remain open until the defrost cycle is over, the compressor comes back on and the temperature of the evaporator coil drops back down to below 20 degrees Fahrenheit. The DTS then closes so that it will be ready to allow current flow to the defrost heater come the next defrost cycle. If you didn't have that 20 degree difference in there, then you'd run into problems with the defrost heater going on and going off repeatedly when the temperature was right around the temperature where the DTS opens, and the DTS would go nutz turning the defrost heater on and off cuz it can't make up it's mind what to do right AT that switching temperature.

So, probably any DTS would work, but I'd try to get one that had the same open and closed temperatures as the Magic Chef fridge did.

If the Magic Chef DTS isn't available, there SHOULD be a recommended replacement DTS listed.

But, I agree with you. Any DTS that opens just above the freezing point and closes again once you're well below the freezing point SHOULD work reasonably well. I think the only reason you'd want to go with one that had the same tripping temperatures is because those temperatures worked fine when they were testing the fridge before it went into production, so those same temperatures should work equally well regardless of who's DTS you use.

Reply to
nestork

magic chef fridge. I was wondering if I can use a defrost thermostat off of a similar GE fridge. they work by opening and closing based on temperature so I dont see why they wouldnt be interchangeable.

Since it's only for the defrost part of the fridge, I'd try it, as long as the wiring matches and the thing can be mounted. The worst thing that will happen is that the fridge wont defrost.

Of course an identical replacement part would be the best solution, but parts like that can be outrageously costly. I'd call an appliance parts house and ask the price, then go from there!

Reply to
mancave

Different brands and models have different temperature settings. But, overall, they are not fussy. I'd go ahead and try it. Should work fine.

. Christ> Any appliance repair experts out there? I have

a bad defrost thermostat on a magic chef fridge. I was wondering if I can use a defrost thermostat off of a similar GE fridge. they work by opening and closing based on temperature so I dont see why they wouldnt be interchangeable.

Reply to
Stormin Mormon

Hmm. This is a learning moment for me. So, please tell me and the rest of the class how a higher temp cut off of the termination stat makes the coil defrost faster? I'll admit, I sure don't see it from here.

. Christ>

be able to cross-reference parts. The exact temperature setting might be stamped on the thermostat. But, I would be skeptical of just blindly replacing one brand with another as you don't know exactly what the manufacturer considers the correct temperature for defrosting. Obviously the temp has to get above 32F, but one manufacturer might use a 40F thermostat, while another uses

45F to get the job done faster. >
Reply to
Stormin Mormon

Kind of reminds me of the folks who put their thermostat heat setting up to 85° believing the house will warm up faster. ^_^

TDD

Reply to
The Daring Dufas

My aunt Myrtle heard it from the hair dresser, who heard it directly from a CIA guy who used to work for.... so it has to be true!

. Christ> >> Hmm. This is a learning moment for me. So, please

Reply to
Stormin Mormon

The temperature at which the DTS opens to cut off power to the defrost heater won't affect the rate at which the evaporator coil defrosts. That's determined entirely by how big your defrost heater is, and how many of them you have. Most fridges have one, some have two. The cut off temperature of the DTS only comes into play after the evaporator coil is fully defrosted and it's temperature starts to rise above 32 deg. F.

Where you need different temperature settings on the DTS is for different evaporator coil designs. Aluminum is a good conductor of heat, but because of the length of the evaporator coil, you could have a dozen or so degrees difference in temperature between one end and the other, or from the side closest to the defrost heater to the side furthest. Having the DTS shut off power to the defrost heater at 45 deg F instead of 35 deg. F helps to ensure the entire evaporator is fully defrosted before you shut off the defrost heater.

So for an evaporator coil that doesn't have internal metal supports to conduct heat horizontally and vertically between different sections of the coil, you'd need a higher cut off temperature so that you'd be sure the entire coil was defrosted before the DTS cut power to the defrost heater. On a smaller coil with metal supports between various sections of the coil that could conduct heat everywhere throughout the coil, you wouldn't have as large a temperature difference between one part of the coil and another, so there you could use a DTS with a lower cut off temperature and still be sure the entire coil was defrosted.

So, the original poster could use a DTS with a cut off temperature of 50 degrees F, say, and be sure his entire coil was defrosted with every defrost cycle. All it would mean is that the overall energy efficiency of the fridge would go down a bit because the defrost heater would stay on until the aluminum evaporator coil was unnecessarily warm. So, it would add a few kilowatts to his electricty bill at the end of each month, meaning that it would cost a few bucks more each month to operate his fridge.

But, IN ALL CASES, the DTS allows full power to the defrost heater until it senses a temperature rize in the aluminum coil above freezing. So, there's no temperature CONTROL of the defrost heater whatsoever... it's either red hot or cold as a cucumber, and nothing in between.

So, after the DTS cuts off power to the defrost heater, the fridge just sits there on it's coffee break until the defrost timer finishes the defrost cycle and diverts electrical power back to the fridge's cold control, and the cold control decides whether or not to turn the compressor and evaporator fan on to cool the fridge down.

PS: For those that don't know, the DTS shuts off power to the defrost heater in the simplest possible way. It's simply wired in series with the defrost heater. So once the DTS opens in response to the temperature rising above freezing, the circuit to the defrost heater is interrupted and no power can flow to the defrost heater.

Everything in the world is incomprehensible until you understand it. Then, it's simple as mud.

Reply to
nestork

If the thermostat is located near the heater, it may kick off before the rest of the house warms up. Turning the thermostat up higher than needed will help to overcome this thermal inertia, permitting more heat to reach the rest of the house in one heating cycle than it would have if the thermostat has to cycle several times.

Jon

Reply to
Jon Danniken

Most sane installers place the thermostat near the air return as is required. The point I was making is that many folks believe that setting the thermostat way past the desired temperature that it will cool or heat faster as though the control knob is like the accelerator pedal in an automobile. ^_^

TDD

Reply to
The Daring Dufas

On 9/4/2013 11:12 AM, The Daring Dufas wrote: ...

you've met my wife?

Reply to
chaniarts

Not necessarily, I've had to deal with a lot of women who find technology to be a mysterious, scary and magical concept that should only be dealt with by properly trained shamans. I don't fault them for their ignorance of technology because they may know many things that I am quite ignorant of but damn! How can somebody be that dumb?! O_o

TDD

Reply to
The Daring Dufas

I just changed one on my Frigidaire. Cost of defrost thermostat at an appliance parts store was $14.87 tax and all. Is it really worth it to use a used one?

Reply to
DanG

And certainly they don't put it where the heat comes out.

The point I was making is that many folks believe that setting

Yep, I know exactly what you mean. They think it puts out more BTUs the higher it's set. The only place it could have some effect is in HVAC where it's multi-stage. If you set it up say 1 deg, it might come on at low stage, where if it were set at 5 deg higher, it would be high stage, so it would be putting out more heat or cooling. But I have a Honeywell VisionPro ther mostat on a 2 stage furnace and the only time it's on low stage is when it's maintaining the temp. If I kick up the thermostat even 1 deg, I've never seen it stay at low stage, it goes to high.

Reply to
trader4

Darn, I forgot about the two stage heating and cooling. I run across so few of them in the area but have installed and serviced the variable speed systems. The HVAC supply houses were selling residential dual staged compressor condensing units at one time but those types seem to have fallen out of favor for the newer variable speed units. Many of the commercial rooftop systems I've serviced and installed have dual compressors that are staged but it's rare to see one on a home. I've never serviced or installed a two stage heating system here in my area unless you think of a heat pump with backup heat as one. I suppose the staged gas furnace heating systems are more useful in colder climates. ^_^

TDD

Reply to
The Daring Dufas

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.