UPDATE: I checked reviews on the LOWES website - the Utilitech bulbs do this for everyone - they are just a crappy product. *** I have replaced several MR16 halogen bulbs in my kitchen with Utilitech MR16 LEDs. Note each is on a separate transformer. After anywhere from 5 to 20 minutes the LEDs turn off (each at a different time). There is still 12VAC at the bulb but its not on. If I unplug a bulb from the socket (with power on) and plug it back in that bulb comes on for a couple of minutes and goes off again. It behaves as if the bulbs are overheating but they are only slightly warm (as expected for a 7w bulb) and the package says use 12VAC which is what I have. Its Weird... Anyone know the root cause of this? (FYI I am tired of messing with this and am returning the LEDs to the hardware store and ordering a bunch of Sylvania halogens from Amazon).

  • are the LEDs hot when the controller shuts off? Most of the LED modules i've seen are 12v, are you sure that's how much your halogens get fed? if you double LED voltage you can draw 10X or more current... – dandavis Dec 31 '17 at 1:50
  • Supply is definitely 12V AC. Separate transformer for each bulb. New bulbs are Utilitech (big company but apparently no web site and no tech support). Package says 12v ac/dc. I.e. they are intended as a plug in replacement for standard MR16 halogen which is what I'm trying to do. I will try to figure out the model and make of the transformers (which are buried in ceiling). – Al Chisholm Dec 31 '17 at 15:08
  • Just checked and there is 12V AC to the bulb even after it goes off (i.e. the transformer is not cutting out). If I unplug the bulb and put it back in it comes back on for a minute then goes off again. The bulb is very slightly warm (as expected for a 7W bulb) but definitely not hot. Maybe I just got a bad batch of bulbs... Tested 3 bulbs in 2 different fixtures. Any way I ordered a bunch of good old Sylvania halogens from Amazon and will return the Utilitech bulbs. – Al Chisholm Jan 1 '18 at 2:49
  • Hello, and welcome to Stack Exchange. First, please edit your question to include all the info in your comments; comments aren't good place for adding information. Second, do the LED bulbs all cut out at once, or one at a time? – Daniel Griscom Jan 1 '18 at 13:25
  • wait, are you saying they stay on for 5-20 mins after the power is removed? – dandavis Jan 1 '18 at 14:44

I had a hard time with mine. First it was because they were on a dimmer. "dimmable" led bulbs are mostly not or at least weren't for my system. Once I swapped out the dimmer I still had a hard time with standard LED bulbs. I had to buy a whole new set of dimmable bulbs to get them working right. Maybe something with the voltage wasn't stable enough? Sorry for the rant but I'm hoping it gives you some ideas.

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