I recently received 4 of the new blue on/off switches. I replaced bathroom fan switches with these. It seems to be working fine in 1 bathroom. But in three of them it initially seems to be working. It initially sits in off mode (with a dim led light glowing), then turned on it also seems to work. But then when turned off for the first time after being turned on, it suddenly seems to shut off (LED shuts off and the fan can no longer be turned on or off). It will not resume until I turn the circuit breaker off and then back on for the bathroom, or pulling out the air gap and pushing back in.
I don’t see anything about overheating when it comes back online and internal temperature is reporting about 35C. The switches are wired exactly they were previously, with the addition of a neutral wire. The neutral is attached to the same neutral as a blue 2-1 in each room. On the blue 2-1 connected to the same neutral (via a wago), they seems to have no problem and it reports itself as having a neutral. I can confirm that the line and load are connected to the right place (putting a voltage detector next to the lower part that says line alerts).
Anyone have any ideas what might be wrong or how I can troubleshoot?
(edited to reflect that this is happening to three of four switches, not one)
Would it be a big lift to try a different Inovelli switch in the same location? It’s interesting that resetting the air gap fixes the issue temporarily. That makes me think it might be isolated to the switch rather than a broader wiring issue. I can’t think of why the switch would lose power when the internal relay opens, considering you’re able to fix it via the air gap. I don’t think the relay closes automatically when power is applied.
Have you changed the switch configuration in any significant way?
On one of the three problem switches, there was previously an inovelli fan switch (not 2-1 or onooff) as that bathroom had a compatible DC fan unlike the other three fans (which never had an inovelli switch installed because they were AC fans). In the DC bathroom, the old fan switch did work just fine for over a month. I decided I wanted the on-off there as well, rather than the fan switch in this location, because I wanted the humidity sensor. However, it seems to be having the same issue as the other two problem switches.
No, the only things I had changed were the led color and autotimeroff on all four switches. I’ve tried resetting them back to the defaults as well.
However, I’m finding out now that the issue is not consistent. Sometimes turning the switch off causes no problems. And then sometimes it does. It is much more frequent in one of the switches than the others. Will post video below.
See video for demonstration. In this case, I turned it on and off once and everything was fine. Then I turned it on and off and the LED stayed on longer than before and then everything just shut off and would not power back on. So far this has happened to 3 of 4 switches, but although I initially thought it happened every time, it happens intermittently. It is not related to how quickly I press off after turning it on.
Woops, sorry! I missed the fact that three switches are having the issue and not just one. That brings me back to wanting to rule out potential wiring issues.
Do you have access to a multimeter by chance? I’d be curious to know some voltages (e.g. line to neutral, line to load, neutral to ground) during these scenarios if so.
I’m assuming the switch is grounded properly? I couldn’t see the wiring in your video.
Ruling some other things out: is this a circuit with GFI outlets? Based on your description it doesn’t sound like this is a contributor.
Are these switches all on single pole circuits?
Is it possible you have a wiring situation that looks like this?
One additional troubleshooting note: when I take the load wire out of the switch, I was not able to replicate the issue until the load was put back in. The fan in the most problematic switch is a Panasonic WhisperWall 70 CFM Wall Exhaust Bath Fan. According to the on-off switch, it pulls around 17W. Although this has happened on 3 of the switches, this one seems to happen almost every time and almost never on the others.
There shouldn’t be any GFCI outlets on this circuit.
I checked ACV and I think i did it right: Switch powered but off:
Line to neutral: 120V
Line to load: 120V
Line to ground: 120V
Neutral to ground: 0V
Switch powered and on:
Line to neutral: 120V
Line to load: 0V
Line to ground: 120V
Neutral to ground: 0V
Switch fully off
Line to neutral: 120V
Line to load: 120V
Line to ground: 120V
Neutral to ground: 0V
These are all single pole wiring, no aux switches.
I am not certain what the wiring looks like behind the fan.
This is potentially your smoking gun and a very important finding. I would expect that the on/off switch could handle a DC motor (inductive load) on the load side just fine. I wonder if back EMF (inductive kickback) is knocking out your Inovelli switches when you turn the fan off.
Unfortunately this is starting to get out of my wheelhouse. I’m not confident in my electrical advice here but you may need something to suppress the voltage spike if that’s indeed the cause of the switches going offline. Here’s an example from Shelly.
Do you have an oscilloscope by chance? I doubt your DMM would capture the voltage spike if one is happening.
It might be the fan. Are they all the same Panasonic Whisper something models? I don’t remember all of the details but there is another thread here where people were trying to use the fan switch with some of the Whisper variants and we’re having issues. Some variants worked and some did not.
That being said, I wouldn’t think that a simple on off would have the same issues as the fan switch, but who knows.
@harjms and others here that had Whisper variants may recall some details.
I believe this fan is AC, not DC. Home Depot says “The Panasonic WhisperWall through-the-wall fan features a fully enclosed AC condenser motor for long-life.”
This is my setup:
Bathroom 1 has this AC WhisperWall fan
Bathroom 2 has this AC WhisperWall fan
Bathroom 3 has this AC WhisperWall fan
Bathroom 4 has a Panasonic WhisperThin, which is a DC
Bathroom 1 experiences the problem almost every time. Bathrooms 2 and 4 experience it sometimes. I haven’t figured out the steps to make it happen consistently. Bathroom 2 previously had a Fan switch and was working just fine with the AC WhisperWall fan, but I figured I would install the on-off for consistency and for the humidity sensor. Since switching from the Fan switch to the on-off switch, it now sometimes fails.
Bathroom 3 has been running the on-off for a week and has not once had the problem (I installed it here first to make sure it would work for me).
I would think that the on-off is for devices like this that wouldn’t have worked on the fan switch. But, everyone reporting issues with the Fan switch and the Whisper models was using the DC Whisper models, which the Fan switch is not supposed to work with.
Copy, I should have been more specific: back EMF can impact both AC and DC fans depending on how they’re designed. It’s very possible that the Panasonic design doesn’t have regenerative energy clamping (sometimes called snubber circuitry). If that’s the case, your neutral line might be carrying this and the switches may be sensitive to the impulse when the fan gets turned off.
I’ll be honest that I don’t understand this, although I’m reading up on it now. If it could explain this, would I expect the results to be so inconsistent if this were the problem?
Bathroom 1: fan causes the problem almost every single time
Bathroom 2: the same fan model bought and installed at the same time, which never once experienced a problem while using the Inovelli Fan switch for over a month, to cause intermittent problems with the On-Off switch?
Bathroom 3: the same fan model bought and installed at the same time to not cause any problems with this Inovelli On-Off switch.
(leaving out Bathroom 4’s intermittent problems, since it’s a different, DC motor fan, although powered by AC as well)
Is there a better way to tell if a fan would be compatible with this device?
The product page states “this switch can be used on any fan or outlet as long as it falls within the max load requirements” but it sounds as if they may not be expected to be the case?
Alright, now I’m confused. I swapped Bathroom 1 on-off switch for bathroom 3 on-off switch. And now both have gone through about a dozen on and off cycles without any issues at all. This would make me think that something was connected wrong, but I had disconnected bathroom 1 completely and reconnected with no change, and really nothing seemed wrong. Bathroom 4 has still had one failure since.
I’m going to factory reset all of them and start all over I think even though I can’t think why this would matter.
I set up a script in home assistant to randomly turn on and off the switches all night. Only one remained with this problem. I completely disconnected and reconnected it. Still the same problem. I did this two more times. Now it seems completely fine?
Really not sure what’s going on. I’m inclined to think I did something wrong, but I have 31 (yes!) blue 2-1s installed and never had a problem. The connections seemed good before: solid copper wires (except for the inovelli included neutral). And the switches would initially work, sometimes for a few cycles, before failing when pressing down. It makes me think there is something more finicky about this model, or some sort of overly sensitive safety feature in the hardware that was getting tripped by the AC fans and maybe after many times it becomes less sensitive?
It wasn’t the physical press of the button moving something because the issue happened even when the switch was toggled on and off over zigbee
If nobody else reports this though, I suppose it was somehow unique to my ability to wire these up.
