Recommendations for HW dilemma

Hardware
1

I’ve found myself in a weird situation where my bathroom switches have no neutral yet by fan exhaust does. I’m not able to install the humidity sensor switch that comes with it or any other smart switch that requires neutral wires as a result. I found these decent Zigbee switches that don’t require neutral and work great for lights but they don’t work for the fan due to load capacity I believe as fan can’t steal enough electricity without a neutral for that smart switch. It seems to only work with a dumb mechanical switch/toggle.

My work around is likely going to be a finger bot to turn it on and off, but I’m hoping for something more elegant.
Also the option to run a neutral wire isn’t really there due to the construction need and spouse disapproval :rofl:

2

Consider using your no-neutral Zigbee switch with no load (“smart bulb mode”), effectively making it a user interface device only. Add a full-wattage Zigbee relay at the fan location, then use Zigbee bindings to make them work as a single on-off pair, working even when HA is offline. Add a Zigbee humidity sensor so HA can be the smarts to determine when to automate the fan during showers.

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3

@peterxian Thanks for that! Can you explain no load smart bulb mode, full wattage relay and bindings?
I have a temp and humidity in the bathroom already so at least that’s covered.
I’ve got this device specifically, but I’m assuming it can’t get into no wattage mode?

4

Normally tuya switches has only basic features, but you can enable smart bulb mode, binding and others by flashing this custom firmware

5

Does your fan have delayed turn off ? If yes, you can use any common smart relay where the fan is located. Have a look what wires you have there in any case.

6

Hi all,
While it sounds like there were a lot of viable options here, I ended up going with the solution proposed by @tim.plas in this thread.

While almost double the price of the Moe’s cheaper Zigbee switches, the Aqara ones are much better quality and does the job!
Spec wise the Moe’s can probably achieve this too but as others have mentioned here, would likely require a different custom firmware. Decided to go with an easier alternative and save my other switch for some lights.

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