I had a 3 new ceiling fan and LED light dimmer installed last year. The dimmer worked great for 9+ months. Recently the light, in all 3 locations, started having problems. At first the lights wouldn't dim, now even when on high the lights will be dim. Occasionally the lights will get brighter for a minute or so, then get dim again.

How do I trouble shoot this. I assume check stable voltage (somehow) at the switch first. If that's good, check at the fan too.

Should I assume I got a bad batch of dimmers and swap them all out?

Clarification: This is 3 rooms, each with a fan&light fixture, each on a different dimmer. The only thing in common is the install date and the model of switch being used.

  • 2
    Do you have 3 dimmers for 3 fans/ lights? Or is one dimmer servicing all 3 fan/lights? Are the lights in the fans dimmable? Was the dimmer part of the fan/ light package or another device added on?
    – RMDman
    Sep 21 at 21:46
  • @RMDman asks good questions. My only comment is I've been pretty disappointed in LED bulbs, they claim to last 20 years, but I've had several fail within 2 or 3 years. I thought they'd be a great replacement for those ugly CFLs, but now, not so much. I buy what I believe are high end bulbs (Phillips), so I'm disappointed several have already failed. Anyway, get back to us with the questions asked above and then we can give better advice. Sep 21 at 23:37
  • @RMDman This is 3rooms not a 3switches on the same circuit.
    – RunThor
    Sep 22 at 0:06
  • 1
    What dimmers are you using? Are the bulbs dimmable LEDs, not all are?
    – RMDman
    Sep 22 at 0:40
  • 2
    While it is a real long shot, since it would likely affect all kinds of things, check voltage on both legs. Simplest way is if you have a clothes dryer or other accessible receptacle that provides two hots and a neutral - should show ~ 240V between hots and ~120V between each hot and neutral. The numbers could be 244V and 122V or 234V and 117V, etc. but they should be consistent on the ~120V side that both hots give the same number. If not, you may have a serious problem with the lights just being a warning bell. Sep 22 at 1:31


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