Repairing a Heat Selection Knob on a Fan Heater

Well this was frustrating! The range selection knob on my fan heater was turning without doing anything. I decided to try and open the case to see what was wrong, but of course the manufacturer had used security fixings, relatively uncommon triangular ones too!

I have lots of shapes and sizes of Torx bits and screwdrivers, but they would be useless in this situation. Luckily I managed to undo two of four screws from the upper side of the heater using a large jeweler's screwdriver. This allowed me to pull the case apart just enough to remove the knob.

Part of the shaft of the knob had snapped off in the switch. Gluing, even with superglue wouldn't be a permanent fix because the resistance of the switch was such that a large torque was needed to change range.
First I removed the broken-off piece of shaft from the switch using a woodscrew. The piece was hollow as was the other piece of shaft remaining on the knob. I decided to attach the two pieces together using a rivet pin.

I hoard lots of scrap, and rivet pins are part of my collection, along with self tapping screws, springs, nuts, washers and all sorts of other miscellaneous items! Some of these pins were exactly the right diameter.

I dripped some super glue into the hollow interior of both sections and also on the broken surface, then joined the two pieces together. Some heat from another fan heater accelerated curing of the glue.

After trimming the pin, I replaced the switch, cost of repair? Zero!