Stylusprotip: name your wifi network [the first 32 characters of the EICAR virus test pattern] if you want your furnace to crash.
we got a new furnace & heat pump a couple weeks ago. This weekend I decided to try its wifi feature (which unfortunately is designed to work only with an internet server controlled by the manufacturer) so I put it on its own isolated wifi network. And playfully gave it that name.
Turn on wifi & scan for networks in the thermostat -> furnace crashes. After a few minutes the thermostat noticed something was wrong and entered a bootloop of solidarity.
About 10 minutes (10 minutes!) after I powered the furnace off and back on using the power switch, we were back in operation. Luckily, the AP name "gaol" doesn't crash anything.
In retrospect I'm just relieved I didn't brick the whole thing. But geez, it's 2025 and your embedded SW can't handle .. punctuation? a 32-byte AP name? idk, maaaannnn.