How I Brought My "Dumb" AC and Fan Into Home Assistant With a Zigbee IR Blaster

[Sarah_D]

I had two devices in my house that refused to join the smart home party: a window AC unit and a ceiling fan, both only controllable by their little IR remotes. I didn't want another app, another remote, or a bunch of tape holding a remote hostage in front of the unit. So I picked up a Zigbee IR blaster and got them both onto my existing mesh. Here's how it went.

Why a Zigbee IR blaster instead of a standalone WiFi one

I already run Zigbee2MQTT on an SLZB-06M, so this was less about the tech and more about not wanting a third ecosystem in the house.

No separate app or cloud account
Joins the same mesh as the rest of my routers and sensors, so LQI and coverage benefit from devices I already have
One coordinator to manage instead of juggling WiFi devices with their own quirks

Setup, start to finish

Paired it in Z2M like any other device (put it in pairing mode, hit permit join, it showed up within a few seconds)
Placed it with a clear line of sight to both the AC and the fan, about 2 meters from each, since IR still needs line of sight even though the mesh side is wireless
Used the "learn" function in Z2M to capture each button from the original remotes, one at a time (power, temp up/down, fan speed, swing)
Named each captured command something sane in Z2M so I wasn't guessing which "IR code 4" did what six months later

The line-of-sight gotcha nobody warns you about

Zigbee mesh doesn't care about walls and IR very much does. I first put the blaster on a shelf that had a clean shot to the fan but was partially blocked from the AC by a bookshelf. Commands to the fan worked instantly, the AC would randomly miss maybe 1 in 5 commands. Moving the blaster about a foot to clear the sightline fixed it completely. Worth testing each command a few times right after setup rather than assuming it works because it worked once.

What this actually got me in Home Assistant

AC now turns off automatically when a window sensor in that room opens
Fan speed ties into a temperature automation instead of me getting up to adjust it
Both show up in the same dashboard as everything else, no separate card for "the IR stuff"

A couple of things I'd tell someone starting this

Capture every button you think you might ever want before you put the original remote in a drawer. I had to dig mine back out once because I forgot to capture "swing mode."
If you have more than one IR device in the same room, check for command collisions. Universal remote codes sometimes overlap between brands.

Anyone else running old AC units or fans through Zigbee IR blasters? Curious what devices you've resurrected this way.