Blue Fan switch with bathroom fan stops working until you power cycle

I wired a blue series bathroom fan switch, and it was working for a couple of days, but then stopped spinning up the fan. The LEDs on the switch were working just fine like they should only the fan would never spin. I though the fan had failed until a second bathroom started doing the same thing. With the second bathroom I was in there when it failed. I noticed that the fan started slowing down and then eventually stopped (I never touched the switch). After that turning the switch off and on did nothing, the fan would not work. I also had a ceiling fan do the same thing, so 3 switches stopped operating for some reason.

I turned off the breaker to the switches and then back on. Once they came back on the fans worked again. I did not change any of the settings.

I’m using Hubitat, and this is a new location for me (vacation house). I’m renovating and replacing switched with Inovelli. I had done this in my main home, and have 7 fan switches there with no problem. the bathroom fans are just your basic dumb fans, and I have them wired properly with neutral, etc.

Any idea what might be wrong? I never had this problem in my other house.

Here is a dump of the registers:

State Variables

  • lastEventCluster : ON_OFF_CLUSTER
  • parameter21value : 1
  • fwDate : 20230824
  • parameter95value : 35
  • lastCommandTime : 2024-Jan-16 10:58:52 PM
  • lastCommandSent : refresh()
  • parameter32value : 30
  • parameter258value : 1
  • parameter98value : 1
  • parameter51value : 0
  • driverDate : 2023-10-14
  • parameter33value : 0
  • lastEventValue :
  • parameter22value : 0
  • auxType : No Aux
  • model : VZM35-SN
  • lastEventTime : 2024-Jan-19 11:11:34 AM
  • parameter52value : 0
  • lastEventAttribute :

Some folks are having the same issue as you with the Panasonic WhisperGreen bath fans. What model is your fan?

It’s just your basic dumb fan, like the Broan you can get at Home Depot:

Broan-NuTone 70 CFM Replacement Motor Wheel for 695A Bathroom Exhaust Fan C370BN - The Home Depot

Definitely not a smart fan by any means.

That’s just plain weird. Particularly with two distinct fan types.

Can you factory reset one and use it for a bit before connecting it to Hubitat. See if you get the same behavior without the hub.

Does it happen quickly once powered up, or could that be a long process?

The fans were on for a while, maybe 30 minutes to an hour. I’ll see if I can reproduce it again, and I have 3 more switches to install on other fans.

Not a solution, but if you need to power-cycle the switch again then you can use the “air-gap” on the switch itself instead of having to walk over to the breaker panel and kill the whole circuit. If you don’t know about the air-gap, it’s the little lever on the bottom, of the paddle. You pull it out to disconnect the switch from power, then push back in to restore power to the switch

Great tip, I’ll remember that