I've researched as well as I could existing posts on this site for 3-way switch configurations and installing a dimmer switch that seem to describe a similar problem, but they always seem to be unresolved or lack enough detail. I have a relatively new home (built 2016) and in the main TV room we have a ceiling fan. The lights can be controlled at 3 different switches around the room. I have had a Lutron Toggler 150-Watt Single-Pole/3-Way CFL-LED Dimmer switch on the main switch plate for about a year [my definition of main plate is the one that is 1.) closest distance-wise to the garage where the breaker box is and generally gets the most action with turning the light on and off based on room placement and 2.) also has a switch to turn the fan on and off].
For whatever reason, if the light has been turned off for awhile, say, overnight, when it is initially turned on if the dimmer toggle is above about 60% or so, when the light is switched on at any wall switch in the room the lights come on and then turn off in about 1 second. You can sort-of hear a "click" when this happens. Occasionally if you keep turning the light off and on it will 'catch' and the light will stay on. If the dimmer toggle is near max (say 90%) it won't ever 'catch', and you'll have to go turn it down on the main switch.
HOWEVER – seems like this is a key detail – if the light has been on for awhile and is 'warmed up', you can push the dimmer toggle up to 100% and the light stays on fine – no issue. The described issue only happens if the light has been off for awhile and is then turned on (e.g., we come home, or first thing in the morning).
I had a Lutron switch on there for a year and thought maybe there was something wrong with it, so bought another identical Lutron switch and replaced it, but it still does the same thing. I took the original switch I had in the TV room and put it in our master bath which has two light fixtures controlled by one switch (ultimately more wattage overall), and it works just fine (that setup just had one switch total to turn the lights on and off).
I have the switch in the TV room wired up just as the original stock one was that was installed when the house was built.
Any of the help info and the instructions only speak to issues where, such as,
+ Bulbs turn off while being dimmed.
+ Bulbs turn on at high light level but do not turn on at a low light level.
+ Bulbs flicker or flash when dimmed to a low light level
but nothing with the issue I'm having. The new one has the Dimming Range Adjustment as shown on the linked product page but that makes no difference with my issue.
I saw a few threads on this forum that seemed to suggest similar issues but the threads never resolved, and the original poster did not include enough information to discern e.g. if the switches or house were new or old, etc, so I started a new one to provide more detail.
The ceiling fan light has three 60w incandescent ceiling fan-style bulbs (smaller), so wattage shouldn't be an issue with what the switch is rated for (and as mentioned, the original switch I moved to the master bath and it works fine with double the number of light bulbs)
The switch works fine, except for this extremely annoying aspect.
Any help would be greatly appreciated.
Best Answer
Well big ups to @ThreePhaseEel for the suggestion to call Lutron customer support. Did not expect them to have 24/7 support, and stateside to boot. I first verified that one of the switches was a 4-way switch (visible even with the panel plate still on as the switch is beefier than a normal light switch) and that I had not messed with that, so was good there.
Lutron support was indeed very helpful - I explained the scenario with what I was experiencing, and the guy said it is probably a "current limiter" on the fan. Apparently all ceiling fans manufactured after Jan 1, 2007 are required to have a light bulb wattage limiter per the Energy Policy Act of 2005 which caps the total wattage allowed to be used by all bulbs at 190 watts. I was using three candelabra-style 60w incandescent bulbs, and as mentioned they did work normally with the dimmer switch after the light and/or switch was on and presumably warmed up after 10 minutes or so. The tech. support guy with Lutron explained that the way dimmer switches work is that they basically cycle the power on and off at about 120 times per second, which matches the line cycle rate or something (I'm not an electrician, obviously). But, he thought the limiter might be interpreting that as some sort of power spike, and I guess when the limiter / light wasn't "warmed up". This made sense as I noticed there was a light but audible click whenever the lights would turn off during an episode of this annoying behavior.
So, to test this theory, I tried turning the light off for a half hour to cool it, and then removed one bulb to reduce the wattage used (now 2 bulbs), and when I turned the light on and moved the dimmer toggle slide up to full blast, the lights did not turn off. This told me that the regular incandescent bulbs in concert with the dimmer and the stock wattage limiter were causing the light to switch off as it had. I ran out and bought 3 60w equivalent dimmable LED candelabra style lights which use something like 6.5 watts each total, and I installed those, and sure enough, they worked perfectly when turning the light on. Good to go.