Thermal Fuse blown on heatgun - suggestions on replacing?

Thread Starter

RogueRose

Joined Oct 10, 2014
375
This is a Chicago Electric 96289 1500w dual setting hot air gun. It just stopped working after being turned off and a minute later, it wouldn't turn on. I checked continuity and everything checks out except the white wire from the power input - which goes to some strange component I'be never seen before which I've found to be a thermal fuse.

What are the "rules" for replacing this and is there anything to be aware of before ordering?

 

shortbus

Joined Sep 30, 2009
7,695
Just like anything else electronic, use the same value of the original. Radioshack, if you have one near you or an appliance parts store should have them. They are used in coffee pots and other such appliances.

The more worrying thing would be the condition of the red wire. What does it connect to? Looks like it may be why the thermal fuse blew.
 

ian field

Joined Oct 27, 2012
6,539
Just like anything else electronic, use the same value of the original. Radioshack, if you have one near you or an appliance parts store should have them. They are used in coffee pots and other such appliances.

The more worrying thing would be the condition of the red wire. What does it connect to? Looks like it may be why the thermal fuse blew.
Looks like the red wire goes to the element - its gonna get hot.

That melted insulation kooks a bit dodgy, but its not the end of the world being next to that mica - I'd probably have a crack at tying it down with some plumbers PTFE tape.

A better repair depends on what connector that wire has on the other end, its possible to salvage wire from a scrap heater that has woven glass strand insulation - if you can get a length with the right connector on one end, that's half the battle.
 

Reloadron

Joined Jan 15, 2015
5,456
I don't know if you will easily find another Aupo Manufacture but NTE makes and distributes them. My guess is you have a 133 degree C version rated at around 15 Amps maybe. The link is to a NTE data sheet so should help. Allied Electronics as well as a host of other distributors carry the NTE line. As a side note most heat guns have a fan only switch position. Following any prolonged use it is best to use the fan only (no heat to element(s) to allow the element to cool. Once the fan stops you can get a thermal rise off the element which can melt a thermal fuse.

Ron
 

hfuser

Joined Jan 20, 2020
4
Just like anything else electronic, use the same value of the original. Radioshack, if you have one near you or an appliance parts store should have them. They are used in coffee pots and other such appliances.

The more worrying thing would be the condition of the red wire. What does it connect to? Looks like it may be why the thermal fuse blew.
This is a Chicago Electric 96289 1500w dual setting hot air gun. It just stopped working after being turned off and a minute later, it wouldn't turn on. I checked continuity and everything checks out except the white wire from the power input - which goes to some strange component I'be never seen before which I've found to be a thermal fuse.

What are the "rules" for replacing this and is there anything to be aware of before ordering?

Hey RogueRose,
I know it has been a long time since your post, but did you fix your HF heat gun?
I have a similar problem with an 4 year old Harbor Freight heat gun. I have continuity on the trigger, which some people have replaced to fix these. I just wondered if you ever fixed yours with a new thermos fuse. I hear they have to be crimped, not soldered as the heat from soldering will blow the fuse. I recently bought another HF heat gun with a HF coupon for only $9.99 plus tax, but still have the old one for possible parts. Took the new one apart and found most everything inside has changed from the old one. No longer a diode on the trigger wiring, My trigger diode tests good. No circuit board on the back of the motor with the 4 small M7F SMD rectifier diodes, but does have larger 4 rectifier diodes 1N4007 with wire leads. Old one did not have a visible thermofuse, but it may be hidden by some heat shrink tape? Looks like there might be something under that black tape? I have not tried to check under the black tape, because I would have to cut some wiring and remove the black tape to see what is there. The one I just bought, does have an exposed thermofuse, that looks identical to your picture and is currently working, but since these cheap heat guns do not have a FAN ONLY switch I suspect if it ever gets too hot with no FAN ONLY switch I might end up blowing the thermofuse.
Did you fix yours?
 
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