I noticed the LED bulb on the circuit controlled by an LZW30-SN glowing dimly when the switch was turned off. The switch reports “0 W” power draw.
I unscrewed the globe and bulb and put a voltmeter across the bulb terminals (it’s a standard US socket - so-called Edison E26). With no load, I measure 31mV AC and 80.1 V DC. Both readings were steady - this is not open circuit noise.
This has been true since I installed the switch four months ago. In all other respects the switch has been working normally . Firmware is 1.09.
It’s possible if unlikely that there is a wiring problem or damaged insulation. Any suggestions?
It looks like you need a “dummy load”. Some led bulbs have this problem. Try with an incandescent bulb, in another socket if there are 2 on the same switch, and it will stop. Maybe it has to do with the way they detect toggle of the dummy switch in 3/4 way setups.
I think there is this issue in a switch also just for a different reason. Do you have more than one bulb on the circuit, or do you have a splitter to add another bulb? I think you will find that it helps this issue.
See also: LZW30 not turning off completely - #17 by Bruskevith
Since the LZW-SN30 supports inductive loads (such as fans), there is a good chance the switch contains a device called a snubber.
Without one, the relay in the switch would slowly destroy itself when turning off inductive loads. The drawback to having one, however, is it allows a small amount of current through, even when the switch is off.
If this is the case, I think the only real solutions would be to either try a different bulb, or try installing a bypass.