Kitchenaid Keys750Lt Thermal fuse above and to the left of the heating coils keeps blowing out within three four days of use. It has continuety when new, but after it blows out the circuit is open and the coils will not heat any more. The only change is a new addition on our house which extended the exhaust pipe, from just outside the washer-dryer room, to up the wall and through the roof, to12 feet from the 12 inches that it use to be. Could this be causing the fuse to short out becaus of excessive heat? Would it be possible to up-grade the fuse to withstand the extra heat?; or is there an inherent problem that stems before the fuse that blows? Regards, Frank

The thermostat is controlling the temperature, however the Heating Coil may be defective. Check the COIL.

If your dryer is not getting any heat, you need to make sure there is nothing blocking the vent. IE: LINT. Air flow is key to efficient drying. Make sure the dryer settings are appropriate for the clothes you want to dry. The timer selection, fabric selection, and the temperature selection all play important roles in proper dryer operation.
Check the heating element, burner operation, ignitor, thermal fuse, and the wiring (power cord).
• Heating element (For Electric Models)
• Burner operation (For Gas Models)
• Ignitor (For Gas Models)
• Thermal fuse
I WOULD START WITH:
To protect from over-heating, many dryers use what's commonly called a thermal fuse. If the thermal fuse gets too hot, it will blow, and completely shut down your dryer until it is replaced. This fuse is often mounted within the exhaust duct in the back panel. It's about an inch long, and is usually found within a white plastic housing. When fuses blow, it means they have no continuity and no power will flow through it. A bad thermal fuse needs to be replaced. When replacing this fuse, check the dryer vents to make sure there is no lint buildup which can cause the heat to stay trapped and blow the fuse again.
Visually inspect your heating element for any broken or burned areas.Check the coil for continuity with a Volt Ohm Meter. If there's no continuity, it means that the element is bad and you need to replace it.
If the ignitor is cycling without the burner lighting, you probably have defective electrical coils in the gas valve. These coils look like black cylinders with wires coming out the top of them, and are located near the burner valve assembly. When they get power, they open up and allow the gas to get through to the burner. If this is a new installation, make sure the gas valve is turned on.

You will have to remove the back panel to access this part. Be sure that you unplug the machine before starting. Once the back panel has been taken off and placed aside the thermal switch will be located on the left lower side near the blower housing . It will be thin and long and located near the cycling thermostat that has for prongs on it. On certain machines, the thermal fuse is located in the front. To access this you must remove the kickplate, which can be done by pushing the clips, one on each side jsut above the top of the kickplate, in between the top and abottom portion. The part numbers are the same for either style dryer. To test this part you can either take the wires off it and tie them together then plug the machine back in and see if it heats, or you can use amultimeter and check to see if there is continuity, if there is its good, if not, bad. The thermal fuse will usually be white, and if located in the back, be thin and long with two wires on it, left and right. If in the bottom front, it will be front center on the exhaust duct. In some cases the ignitor or the gas coils will go bad. Here is a good process of elimination.
1)Verify that the thermal fuse is good. If you don't have a meter bypass it and turn the machine on. If heats, thermal fuse is bad, if not leave connected and continue
2)When the dryer starts and thermal fuse bypassed, the ignitor should start to get hot and glow, if your thermal fuse is in the back you are going to have to have to the top of the dryer up to see down inside near the front for the glow. You can do this by taking the lint trap out and removing the two screws and popping the top up. If the ignitor comes on more than likely the gas coils are bad and if it doesn't the ignitior is bad. (this is while the thermal fuse is bypassed so the ignitor has power to it regardless)

If you need further help, I’m available over the phone at https://www.6ya.com/expert/jason_4570d45317834dd3

You will have to remove the back panel to access this part. Be sure that you unplug the machine before starting. Once the back panel has been taken off and placed aside the thermal switch will be located on the left lower side near the blower housing . It will be thin and long and located near the cycling thermostat that has for prongs on it. On certain machines, the thermal fuse is located in the front. To access this you must remove the kickplate, which can be done by pushing the clips, one on each side jsut above the top of the kickplate, in between the top and abottom portion. The part numbers are the same for either style dryer. To test this part you can either take the wires off it and tie them together then plug the machine back in and see if it heats, or you can use amultimeter and check to see if there is continuity, if there is its good, if not, bad. The thermal fuse will usually be white, and if located in the back, be thin and long with two wires on it, left and right. If in the bottom front, it will be front center on the exhaust duct. In some cases the ignitor or the gas coils will go bad. Here is a good process of elimination.
1)Verify that the thermal fuse is good. If you don't have a meter bypass it and turn the machine on. If heats, thermal fuse is bad, if not leave connected and continue
2)When the dryer starts and thermal fuse bypassed, the ignitor should start to get hot and glow, if your thermal fuse is in the back you are going to have to have to the top of the dryer up to see down inside near the front for the glow. You can do this by taking the lint trap out and removing the two screws and popping the top up. If the ignitor comes on more than likely the gas coils are bad and if it doesn't the ignitior is bad. (this is while the thermal fuse is bypassed so the ignitor has power to it regardless)

If you need further help, I’m available over the phone at https://www.6ya.com/expert/jason_4570d45317834dd3

Hi,
One of the heating elements is stretching enough when it gets really hot and it is touching a metal part somewhere which blows the fuse...

Pull the heating element part out and you should be able to see where it is arcing and causing the short...

heatman101

Have you cleaned the blower vent pipes lately. Sounds like the vents may be stopped up with lint and it got too hot. Clean vents and where the fan blade is to be sure the fan can turn. I have found everything you can think of in the blower housing that would keep the fan from turning.Be sure and get the lint out they all have some. As far as the heat not working check all thermastats , the thermal fuse on blower box and thermal cutoff usely on the heater box. and the heater coil also check with an ohmeter from heater coil connections to the metal box it's in ,the coil could be grounded inside the box.
Hope this helps.

Hi,

Hi,

Thermal Fuse is located inside the dryer, If the thermal fuse gets too hot, it will blow, and completely shut down your dryer until it is replaced. This fuse is often mounted within the exhaust duct in the back panel. It’s about an inch long, and is usually found within a white plastic housing. When fuses blow, it means they have no continuity and no power will flow through it. A bad thermal fuse needs to be replaced. When replacing this fuse, check the dryer vents to make sure there is no lint buildup which can cause the heat to stay trapped and blow the fuse again.

Good luck and have a nice day
Rating the solution is highly appreciated.

The little white part with one hole is the thermal fuse, similar to the cutoff but service a different purpose.

The cut off will blow if there is lack of air flow, typically a plugged vent or lint screen.

The thermal fuse will blow if the exhaust temperature is too high. The reason the temperature is too hot can be one of two things.

#1 and most likely is the component right next to the thermal fuse, it is the operating thermostat.

#2 A shorted heat element that is on all the time, this can be checked by turning the timer knob to 30 minutes on the timed dry cycle, close the door but do not start the dryer. Open the door after about 2 minutes and see if the drum is hot. If it is not the element is okay.

I hope this helps

Check the heating element and thermal fuses for continuety

try replacing thermal fuse. its cheaper than the heater element. this fuse blows when there is restricted air flow over the heating element. meaning clogged vent. you can ohm out this fuse. fuse is located at top left of heater duct with two wire leads going towards it. if its ok then remove heating element and look at coils. usually you can see one broke