Thread: What is the normal temp of a dimmer switch?

Yhey get hot....they are a reostat or varable resister so yeh they lower voltage by adding resistance....resistance will create heat. How much temp is normal I have no idea but I bet Speck can tell you.

I've had that problem especially when you have more than one dimmer in the same junction box.
First thing is to make sure you have adequate ground for the load the rheostat is controlling. Ground will help reduce induction heat inside of the junction box.
If it's on an inside wall (uninsulated) I have drilled a hole (in plastic boxes) or opened one of the knockouts (in metal) on top of the junction box to let the heat escape.
Make sure all of the junctions are spliced well so you have no arcing.
As "G" said, they will get a little warm from resistance but yours sounds too warm.

Your rheostat may also be going bad. Hopefully if everything else is good, your new stat will solve the problem.

Ain't no lectrician but are you running florescent bulbs in your fixture. I know I picked up one and was going to install and instructions said no Florescent bulbs just incandescent. Those bulbs would cause it to overheat. Never had one get near that hot. Gene, just for grins you might just wire in a regular on/off switch and take it's temp. If it gets hot then start looking for a problem.

Thanks. They are not florescent. Thought about the one we have on the back deck. It's a 600w running 4 75w bulbs. I placed the thermometer in it and turned it on full. After 15 minutes it was on 135 degrees. The thermometer is tight between the front metal plate of the switch and the face plate.

Gene....check your temps with it set on low....the lower you set the switch the more resistance....thus the more heat.

Originally Posted by "G"

Gene....check your temps with it set on low....the lower you set the switch the more resistance....thus the more heat.

That's what I thought too. I lowered the light on the 1000W and the temp fell a few degrees. Haven't checked the 600 W.

interesting....I really dont think 135 is too hot for that.....but thats just a guess......I bet as you increase the resistance....you are decreasing the load ( wattage) so I guess that would lower it.