LED only flickers at the low end, how do you tell if it’s the dimmer or the driver?

[TankReyn]

I’m dealing with a weird one and I’m trying to figure out if I bought the wrong dimmer or if the LED setup itself is the problem. The lights look totally normal at full brightness and mid range, but once I dim down near the bottom they start doing that annoying flutter flicker.

A specific moment was last night when I tried to set a low cozy level and it looked like the lights were breathing. What’s your go to way to confirm dimmer compatibility versus a driver issue, and what’s the simplest check you do before swapping parts?

 

[Alan]

Low end flicker is usually a dimmer compatibility issue or a cheap LED driver that cannot handle the chopped waveform. First check if the dimmer is actually rated for LED and whether it is forward phase or reverse phase. Then try one known good dimmable LED on that circuit. If one quality bulb behaves and the others flicker, it is the driver. If everything flickers at the bottom, look at the dimmer and its low end trim setting.

 

[General_Valeria]

I start simple. First I check the bulb or fixture box for “dimmable” and any dimmer model list. Then I try one known good dimmable LED in that circuit. If the flicker only happens at the very bottom, a lot of times it’s the dimmer low end setting, if the dimmer has a trim. If there’s no trim, I usually suspect compatibility.

 

[Electro29]

A simple way to separate the two is to test the LED at full power on a known stable circuit then bypass the dimmer entirely if possible and run it direct.

If it’s clean direct but flickers only on the dimmer at low end, it’s almost always a compatibility issue between dimmer type and driver. If it still flickers direct, you’re looking at the driver or LED itself.