Replacing Light Fixture Dimmer Q&A

Be sure to scroll down... there may be more than one question on this page!

Dear NH,

I have a light switch and speed control rheostat for the ceiling fan on the same faceplate. The faceplate becomes very hot after the fan has been on for a few hours. I also detected an odor coming from the faceplate area. Since the rheostat is 14 years old, I decided to replace it, hoping to correct the problem. The wires all look good, but I am worried that there may be a more serious problem. The smell was very pronounced when I removed the cover. What do you think?

IV from points unknown


Replacing the speed control was a good choice. They do absorb power, especially when used at low settings, get hot (which is normal), and eventually burn out.  It is an escalating phenomenon... as they begin to get hotter the lifespan of the switch drops quickly.

Since you did not notice any heat damage to the insulation on the wires, I think that you have completed the correct repair, based on the info you gave me.

Just a note: Dimmer controls for light fixtures work on the same principle and also eventually fail for the same reason... the long-term effects of heat buildup.