How to solder in a thermal fuse ?

Thread Starter


Joined Sep 29, 2017
We have an appliance that blew a 123C, thermal fuse. I bought 5 of them and so far have blown 2 of them.
My soldering iron has a lowest setting of 200C so I am at a loss as to how to do this.
Is there such a thing as cold solder ?
Maybe google will tell me but I trust youmore.


Joined Sep 9, 2010
Many times these are crimped onto bare wires. If you can’t do that, I’d solder as far away from the fuse as possible and use a rubber band to clamp some pliers between the fuse and where you’re soldering. Hemostats are handy for this also.


Joined Oct 29, 2013
Try a heat sink and a hotter iron. When the iron is not hot enough it takes longer to get the spot that you're soldering hot, which gives more time for the heat to propogate through the rest of the part. With a hotter iron, you can heat the area you need and get the solder on there faster, giving less time for the rest of the part to heat up. You can get clamp on heat sinks on Amazon for a couple bucks.