Tonight we noticed that despite our Nest Thermostat saying it was heating the house, the furnace was in fact not kicking on. I was worried my furnace had blown another ignitor (as it’s prone to do every few years), but I couldn’t even get the fan to turn on.

I decided to call Nest support before the furnace repairman, to make sure it wasn’t something wrong with my smart thermostat. We ran through a bunch of different troubleshooting and eventually what solved the problem was just pulling and re-attaching a couple of the wires.

What struck me about this problem is that it wasn’t a software bug, or a firmware update, but something in the raw voltage that wasn’t working right. At the end of the day, this mini-computer that is controlling the climate in my house, is still beholden to the simply physics of volts and amps on copper wire.