Tracking down a temperature sensor issue (learn from my fail)
My house is wired six ways to Sunday. One of the things I have a lot of is temperature sensors because I reviewed them, and because in a 1940’s house that was updated to central air conditioning by I’m guessing the lowest bidder in 1986, I have issues keeping any one room the right temperature.
This wasn’t such an issue before I had tiny little people who lived here and occasionally fell asleep and half froze to death because they just don’t wake up, but it became an issue. As such I’ve got warnings any time either of the kids rooms are above or below a certain temperature.
I’ve also got all sorts of automation so that the instant the house is abandoned we’re not spending money to heat and cool it beyond a certain point.
Recently these two systems started butting heads. I’d walk out the door and within an hour start getting a notification, usually around 8:30 that the house was unusually hot. This is a problem because I do have equipment that needs to be cooled, and so I’d jump into the Nest thermostat and notice the temperature was quite normal, but kick on the fan to circulate air or put on the AC just to cool things down.
Usually in about an hour the temperature warning would go away, and I didn’t think much about it.
Due to some reasons I’m at home today. Nothing exciting or interesting unless fixing a leak in a window seal is your idea of an exciting Tuesday. I got the notice that my living room was excessively hot and went to turn the fan on and realized that 1) I was in the living room, 2) it was not excessively hot.
I did a quick temperature check and decided I did not have a fever, the room was about the same as any other, and I felt around the sensor (an Airthings and while slightly warming it was not the temperature it was reporting.) Did I have a bad sensor? But it was warmer there…
Oh right, there’s a freaking star outside the window that’s visible and its rays come in roughly an hour and a half and directly bake the Airthings sensor. Head desk. Yes, the sun was shining directly on the sensor for an hour or so every morning and was responsible for days of fan running. Now, it wasn’t just the Airthings that had reported that, I’d had a different sensor reporting that prior… however both were sitting in the same place… in the sun…
They weren’t in the sun when I left in the morning and they weren’t in the sun when I got back in the afternoon.
But yeah, I should have caught that..
Learn from my fail kids…