I’m using a GE - Z-Wave Plus Wireless Smart In-Wall Fan Speed Switch (Model: 14287) to control a Kichler 52-in Nickel Indoor Downrod Mount Ceiling Fan (Model # 35286).
I have the exact same setup in my office and in my bedroom. Neither have the control guts that came with the kit, just using the wall switch. (Both have dedicated GE Light Switch for the fan light)
The one in the office will shut off after a couple of seconds when it is under 70% while the bedroom one runs perfectly at any speed.
I do have the 3-Speed Fan SmartApp loaded, but even with that out of the picture the Office fan still shuts off.
I have replaced the GE Fan Switch with one of my spares and it has made no difference.
Any ideas short of replacing the whole fan?