So I finally installed the proper Mitsubishi branded wifi adaptor (MAC-559IF-E) in my heat pump (MSZ-FB50VA).
One of the big drawbacks about this adaptor is that it requires a router with WPS, but as most of you will know WPS is not recommended from a security point of view. In addition, many routers don't offer the function at all (including my UniFI AP).
I found it was actually very easy get make it work with my UniFi:
- Power off UniFi
- Setup any old spare 2.4GHz AP with the same SSID and PSK as you normally use on your UniFi (I used my old Fritz!Box 7390)
- Join the wifi adapter to the network via WPS and setup in app.
- Power off old AP
- Power on UniFi
The Mitsubishi adaptor will now happily connect to your UniFi with no WPS needed. I fully cut power to the heat pump to check that it will remember it's settings after a power outage, and it still happily reconnected to the UniFi.
I had read in several posts that it is not suitable using your phone as your main remote as there is a delay of up to a minute before the command is actioned, but for me this only appears to be the case if you are not on the local network. When on the local network commands are being actioned within a second or two. I only experienced the reported delay when I disabled wifi on my phone and did it over 4G (however if I established a VPN while on 4G I again did not experience the delay). Maybe this is an improved feature from the (presumably older) MAC558IF-E, although I can find no info on what the differences between these two adaptors are.
However, there is a delay of a minute or two on the app updating the status of the heat pump if the settings are changed from the normal remote or from someone using the app on another device (their app updates straight away when they change a setting, your app might take a couple of minutes for their change to show up). In real world usage I can't see this being much of an issue.
I haven't tested yet to see if the app works on the local network if there is no Internet access, I will try that tonight.
Cost of the adaptor was $195, so not bad since it is the official Mitsubishi one. The physical installation wasn't as straight forward as I was expecting though.