I had on office tenant complain that the heating thermostat was not working. I sent a mechanic, who came back and tossed a rusted out hunk of junk on my desk, and said that was the thermostat. He had replaced it, but that was what was left of the old one.
About a month and a half later, I get another call from the tenant complaining about a failed thermostat. Again the mechanic came back with a rusted hunk of junk.
I examined the rest of the thermostats we had in stock, and they looked fine. I asked the mechanic, and he said that the new stat had been purchased elsewhere.
I was puzzled until one day I was walking through the space, and noticed that a certain tenant employee had taped an ice cube to the top of the thermostat, presumably to make the heat come on. Apparently he had been doing this every day for years because he couldn’t figure out how to use the dial. I showed him how the dial on the front of the T-stat turned to set the temperature, and we never had any problems after that.
Oh man good thing it wasn’t a 120VAC tstat!
I’ve come across some good design issues, best was a new house with the thermostat directly in a registers airstream. Heat would come on for a minute and shut off even though set at 80, thermostat was happy but the rest of the house was freezing.
Now that's "Thinking Outside the Box", LOL!