I turned on a light switch and noticed a few small sparks inside the
switch as I turned it on. No big deal, or so I thought.
After the lights were on for awhile I there was an 'electric burning'
smell. Sure enough the switch was hot to the touch.
Is it likely that the switch itself is bad and that replacing it will
solve the problem? (That I can easily do myself.)
Or could it be a more serious problem for which I should call an
Thanks in advance for any help...
It could be a bad switch. Or it could be loose wires at the screw
connectors. It's easy to change the switch. Try that first. Of course,
kill the power first before changing the switch. If it's just a regular
2 wire switch, it does not matter which wire goes which.
Try replacing the switch, making sure to use the screws to attach the
wires firmly to the new switch. Don't use the back stab wire inserts.
Also, if the wire insulation has become brittle, make sure to wrap it
well with good electrical tape, or if you have enough slack in the
wire, cut the wires back to where the insulation is pliable.
Also, before turning the power back on, check the wires in the
junction box that the light is attached to. Make sure they are in good
shape and attached firmly. If the insulation is brittle, cut back to
where it's pliable if slack permits, or wrap well with good electrical
Watch carefully. If the switch gets warm again, something else is
wrong, and you'll need to get it diagnosed.
Most likely a bad 50 cent switch. The sparks indicate a loose connection.
If it is a single switch circuit you should be able to do it yourself with
no problems. Just be sure to turn the breaker off before you start. If it
happens to be a three way circuit pair a pair of switches, replace both and
do one wire at a time.
Not really sure why you'd need to replace both switches, other than "if one
is bad, the other must be close". But with that mentality should't he be
replacing every switch in the house, assuming they're all about the same
Also, no need to do one wire at a time -- just make sure you remember what
wire went where.
The traveler connections are in different locations on different brands.
The color coding if present varies also. The suggestion to change both at
the same time is just to keep it simple for the next DIY guy.
Actually it's more like a $5 switch :) It's a Decora style dimmer with
a rocker switch.
It wouldn't surprise me to find a loose connection in there. Some of
the electricians that did the work in my house were a bit careless.
Since it is a dimmer, I would check to see what the load is. The average
dimmer is rated for 600 watts, but a combo type with separate switch may
only be rated for 300 watts. If the load is acceptable then do as others
have said and shut the power off and replace the unit. When replacing, only
remove the wires from the dimmer. Do not take apart any other wires in the
box that are not connected to the dimmer.
John Grabowski ( firstname.lastname@example.org) said...
Also, be aware of derating issues. Many dimmers rated at 600 Watts have
a derated value of 500 Watts for ganged installations.
This means, if the dimmer is installed in a location all by itself, or
if it is a ganged location where it is the ONLY dimmer, then the 600 Watt
rating applies. If it is in a ganged box with another dimmer, then it is
only rated for 500 Watts.
"Never ascribe to malice what can equally be explained by incompetence."
On Sat, 8 Oct 2005 19:01:14 -0400, "John Grabowski"
Wow, thanks for the information. I didn't even think of this. It is
controlling 6 100W flood lamps and may indeed be overloaded. Though it
has been running this way for over 3 years now...
I assumed that since it was installed by pros as part of a total house
electrical upgrade, that they knew what they were doing. But clearly
there was at least one bad apple in the group because I later
discovered that they wired one of my ceiling fans incorrectly.
Boy, if you can buy a Decora style dimmer for $5, sign me up. I'll take 50.
The sparks aren't necessarily a problem as all wall switches spark when they
make and break a circuit. You just usually can't see the spark inside the
plastic. Lutron has had issues with this for years on their Skylark models a
spark is clearly visible at the sides of the rocker switch, which scares the
bejeebers out of a lot of folks. The burning smell on the other hand is a
good indication of a problem, so the unit should be replaced. The aluminum
face of the dimmer is a heat sink and in normal operation will get pretty
hot, so just be sure not to overload the capacity of the dimmer
On Sat, 8 Oct 2005 19:38:44 -0400, "RBM" <rbm2(remove
Yep, this is the one I have (unless its one that looks exactly the
same). I've seen sparks from time inside the switch but didn't worry
I didn't realize it was a $20 switch. I think I'll go to Home Depot
and downgrade ;)
With sparking and a burning smell, I would be concerned with the
insulation on the wiring. If you are confident that it has not been
impaired, or that you can shorten the wire to where the insulation is
good, have a go at it. If you are uncertain, call an electrician.
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