I have just had 4 of the Mercator AC Fan Controllers installed in my home (AC Fan Controller | Ikuü).
I am so VERY disappointed in these things. DO NOT WASTE YOUR MONEY!!!.
The controllers paired with ZHA without and issue, and I can control the fans and lights flawlessly. You’re probably thinking at this point, well what’s the problem.
The problem is that all 4 of the controllers will consistently reset (LED indicators turn white and then everything turns off) if you try to change the fan speed from the physical buttons on the wall. I’ve been in contact with Mercator and provided a video of the unit doing this and so far the response has been, and I quote.
Please be advised that the smart fan speed controller is designed to use it from the App only and not by the physical buttons.
So despite them having physical buttons, they are not designed to be used and do not function as expected and Mercator seem to know this and seem to think its perfectly OK.