Blue 2-1 Voltage on Load while Switch is Off with Neutral

I’ve gotten a lot of my Blues in and I’ve been noticing something really strange. Basically all of my Blues leak power to the Load wire while Off even with Neutral wire. For a “No Neutral” I would expect this as that is how it is powering itself…but why is it happening when there is a Neutral wire?

Note that my switches function perfectly and they do have power source as “Neutral” when I look at the device in Hubitat. So it knows it has Neutral. Their latest firmware and latest Hubitat driver. But they still leak power to Load wire. I know this from checking with a good meter while installing and also from several installed switches having faintly flickering load LEDs while Switch is off. I’m sure wiring in a bypass would solve that flickering, but it also just seems wrong that it’s happening at all with Neutral wired in.

Am I missing something?

First off are you measuring Voltage or Current (or both)? Voltage can be present without current flowing.

But also, remember that the Blue Series auto-sense the neutral/non-neutral wiring. Its not a setting you turn on or off. As far as I know, its always auto-sensing, and not something that only happens at boot up. I’m pretty sure it needs to leak a very small amount of current to do that

Why does it need to leak to Load to detect if Neutral is there? So it can automatically fall back to Non-Neutral if the Neutral wire magically disappears? That makes no sense.

What’s even the point of Neutral mode then? Basically 99.999% of the advantage of having Neutral is so you DON’T leak to Load and have flickering lights while switch is OFF. If it’s going to do that anyway, it seems like a waste of time to even bother wiring in the Neutral wire IMO.

Also just to answer this because I didn’t…I see both on the meter. Flickering lights also means both.

I’m just speculating. I don’t have the specific details of the method used to auto-sense. My personal preference would be that it only do it at power-up and then stop sensing until the next power-cycle.

You said you measured current. What did you see? It was my understanding that auto-sensing current is extremely small… like micro-amps… which is not enough to cause flickering lights or power the switch itself. Neutral is the path for the milliamps needed to power the switch without going through the load

Same…absolutely. I honestly just assumed that’s the way it works. I’m honestly surprised if it’s not like that to be completely honest.

I have flickering one that’s just a single LED bulb as Load and another that are two can lights with LED bulb. I don’t recall the current reading I just remember being surprised it was >0…I had only pulled out the meter because the live wire pen was beeping on it.

Just took a stroll through the house while all the switches are off…the loads on every single Blue are on. Only those few got noticed because of flickering but every single bulb is “on” at a very low level. Not gonna lie I probably wouldn’t have bought a ton of these Blues if I had known about this problem. I can’t go around and wire in a bypass to 50+ lighting circuits. :rage:

Generally speaking, ALL dimmers will leak to some extent. This is true for both smart and dumb dimmers. It’s the nature of how the MOSFET, TRIAC or whatever they are using works.

This is why there is an air gap on dimmers. There is a safety requirement (UL maybe . . 1472??) to fully disconnect a switched device from the power, and the airgap provides that function.

At the present, the MOSFET is employed for both dimming and on-off functions for the Blue, so it’s a dimmer regardless of use. There has been discussion here of getting the Blue to produce a full sine wave output when in the on-off mode. If Inovelli is able to implement that, that MAY isolate the MOSFET routing only through the relay for the on-off mode. If that occurs, that should solve the leakage issue for the Blue in the switch mode.

But dimmers, any dimmers generally speaking, are going to leak. It then depends on your bulb whether or not they will glow as a result.


Probably cheaper to install new bulbs.


Are they hue bulbs? There is a known hue firmware update that fixes them not turning off at low power.


Probably not in my house. :rofl:. This builder must have an inside man at the can light factory because there’s a ton of them absolutely everywhere in this house. It’s kind of absurd.

Nope. All various supposedly-dimmable LEDs.

Are there any you can swap in an incandescent for a sanity check? If the incandescent works fine it’s the LED. If not, we can help you further troubleshoot. The blues use leading edge dimming. This is not compatible with all LEDs but was necessary current design.

1 Like

There should not be any voltage at all when attached to a load with the dimmer in the Off position (and using a neutral wire). It is of course entirely possible to turn a MOSFET or TRIAC completely off. And I am curious why the relay also isn’t being opened at full off. It sounds like possibly a bug with the neutral sensing circuit. I’m also confused why there is both auto-sensing AND a config parameter for the neutral wire.

Eric, do you have any thoughts? I just found out about Inovelli and am interested in the Blue, but this would be a deal killer if it isn’t resolved.


I believe it is r/o but there so it can be queried and displayed.

Regarding your first question, the use of the MOSFET for both dimming and switching and it’s adverse implications (sine wave, etc) has been discussed ad nauseam here. Take a look around and you’ll find a number of threads. I know there is a lot here making some things hard to find, so the TLDR is that Inovelli is aware of the issue and is presently seeking solutions.