I've had it with the ridiculous #Kumo Cloud-based #Mitsubishi thermostats use.
The thing randomly forgets the schedule and sits there claiming it's following it when in fact it didn't adjust the temperature up or down as it specified. Usually it's been forgetting to turn the temperatue down at night every week or two, but the other day it forgot to turn it up in the morning.
Mitsubishi's solution to this is to give the thermostat its own wifi hotspot. But first of all, who in hell makes a thermostat that requires network access to change the temperature? And secondly, that's bull. It made no difference whether I used their hotspot or mine. Online forums make it clear that this problem has existed for years.
So now I get to throw away the money I paid for a lifetime cloud subscription, buy an adapter that makes it work with third party thermostats, and pay someone to install it. Oh joy.
The only bright side is that I kept my old Nest.
It's not the only problem. If you want the heat to go up fast (which with a heat pump, means switching to electric heat mode, which isn't efficient, your only option is to crank the temperature up. The Nest will let you override the eco mode. It doesn't take into account outside temperatures, so when it's cold out and the only option is an override, it doesn't do it unless the temp drops about three degrees below setting. So it will sit there all day colder than I want. In fact, it rarely keeps the temperature at the specified setting. The HVAC system itself works great, but the thermostat is a piece of garbage.