Heating element in food dehydrator not working

Stan in Oly, WA

Well-known Member
My wife got a food dehydrator at a garage sale, brought it home, and plugged it in to test it. It worked for a while---the fan ran and the element heated---then it stopped working. She thinks that some solid baffles on the bottom rack which she didn't know enough to remove may have caused too much heat buildup. Anyway, now the element won't heat.

I took it apart and it appears that the problem may be at an electrical component between the potentiometer and one end of the element. It may be a fuse. It is about 1/2" long and 3/32" in diameter between about an inch of stiff wire at each end. It resisters as an open circuit on my ohmmeter at every potentiometer/temperature setting. Is it likely to be something other than a fuse, so that I would do more damage if I were to jump around it to test the element?

My wife found the parts list and drawing online, but the drawings and the numbers are too poor to read. The list does include a fuse, and no other electrical component such as a resistor that I can see. The dehydrator was sold by Sears. I have had bad luck getting parts for old Sears appliances, but something standard like a fuse should be available elsewhere.

Stan
 
In my original posting I typed "resisters" when I intended to type "registers". The sentence "It resisters as an open circuit on my ohmmeter at every potentiometer/temperature setting" should read "It registers as an open circuit on my ohmmeter at every potentiometer/temperature setting."
 
Thermal fuse. Jump around it for a bit and see if it works. But, if it is a thermal fuse, replace it.
 
Yep. And make sure you have a heat sink when you solder it in.

Got one for a bathroom fan/ heater at radio shack once, at least 10 years ago. They ID by the color band on them.
 
It's a thermal fuse.

It is a safety device to prevent the machine from overheating and causing a fire. This didn't blow because of a current overload, but because it overheated, probably because of the baffles you mentioned. But, it could have also been caused by a defective thermostat or another component designed to regulate the temperature.

Manufacturers often include these fuses in the circuit to protect themselves from the liability of the product malfunctioning. It's a one time failure designed to disable the product, not intended to be returned to service.

The thermal fuse should only be replaced by one of identical value. If the machine manufacturer offers a replacement, might be worth the effort to replace it. Just don't risk creating a dangerous situation by taking a shortcut!
 
You used to be able to get them at radio shack. Allied radio has them too. Also check Flea bay. Also check your local appliance parts joint.
 
My wife was a department supervisor (25 years) at a company that made electric heating elements. Everything from hog trough heaters to heaters that were used to bake the paint on helicopters for the military.
With that said, she said you are talking about a thermal coupler. Not knowing what brand of dehydrator you have it is hard to say what element you have. It may not be worth the effort to repair it.
 
Rollie;

I've replaced thermal couplers (AKA thermocouples) in furnaces and water heaters. It isn't that. It's a thermal fuse. I took the dehydrator apart and the fuse is accessible (and matches the online pictures). I jumped past it with my very dangerous alligator clips on a lamp cord, and the element works fine. I can get a replacement fuse online for $0.99 plus $5 shipping. Now that Radio Shack is gone, I have no idea where I would go to buy one locally.

Stan
 

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