Switch – faint LED glow when smart dimmer switch is off

dimmer-switchlightswitch

I have a TP link HS220 dimmer switch that appears to be working correctly with the Phillips 8w LEDs I have. It goes on/off min and max dim with no issues. However, when I turn off the switch there is a slight glow coming from the LED light. This dimmer controls 2 LED lights and you can see the faint glow on one of the lights. 🙁

The way I installed this is not typical because the circuit actually goes to the light 1st then to the smart switch, so at the switch I have a 14/2. I have the black going to the hot screw and the white wire going to the load. Luckily this switch is installed on a 2 GANG box that also has a fan switch. The fan is using a 14/3 wire and one of the wires is no longer being used by the fan. This was the wire that controlled the fan light. So I took this wire and connected it to the neutrals at the fan box in the ceiling and then connected the other side of this wire to to the smart dimmer on the neutral pigtail (both wires go to the same breaker). Again, all appears to be working but when the switch is completely off, you can see a glow coming from the LED light.

I'm trying to determine if its my wiring that is causing this glow or if its the switch. I'm not an electrician and would appreciate any help in trying to figure this out.

TIA, P

Update, I did eventually get rid of the faint glow with a better bulb. I used the GE reveal 10w BR30 and this removed the glow. I also realize I have some code violations the way I wired things. Since I have no neutral I will be moving to a Caseta dimmer at some point and removing the TP link
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Best Answer

I can't say for sure why you have that LED glow. Typically that is due to deliberate power leakage through switched hot for a switch that doesn't require neutral. However, this switch requires neutral and you have described a wiring installation where it gets neutral. So the mystery remains. But you have bigger problems.

The neutral/hot/switched hot need to be together. Not going to immediately cause a big problem in your current (pun intended) setup because LEDs don't use much power, but definitely against code and not good long-term. In addition, you very likely have a color-coding problem.

Here are the key things:

  • Neutral must run together with the other wires of the circuit. In some cases you don't need neutral - that's why your switch loop didn't have it. New code requires neutral at switches to take care of this problem, but old wiring is grandfathered. Grandfathered wiring takes care of the code issue until you actually need the neutral! So for this setup, you either need a new 14/3 cable to replace the 14/2 (so you can get the correct neutral) or you need a switch that doesn't require neutral.
  • Wherever you do get neutral, it must be white or gray (or grey). Based on your description, you very likely repurposed an unused red or black wire to be neutral. You are permitted to use a white wire in a cable as hot or switched hot under limited circumstances, but you can't use a colored wire as neutral.

Part of the problem is that historically dimmers, timers, etc. would leak current through switched hot to power themselves. That works great with incandescent lights. With LEDs, that results in either a glow or (even worse) blinking. The solutions are:

  • Battery - You have to change it periodically.
  • Neutral - You have to get a neutral in the right place (as you found out the hard way). Which is why code now mandates neutral in switch boxes.
  • Ground - Permitted under limited circumstances when designed properly and approved.

End result: You may need a different switch. But if the switch (this one if the problem can be fixed, or another one) needs neutral, then you will need a new cable - you can't grab a neutral from elsewhere, even though it is on the same breaker/circuit.

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