It finally got cold enough at the house to turn on the heat, for the first
time since last winter - and - and - nothing happened.
The heat didn't go on all night, so this is what I saw in the morning:
I really do not understand how home heating systems work.
I figured I'd start by taking apart the thermostat to see if I can test
if it's giving the right signal to it's Payne 394JAW propane heater:
The little mercury bulb appears to work, at least at the extremes:
And, there's this calibration thingy that seems to be already set:
But, I couldn't see what I'm supposed to *test*
without removing screws:
Yet, once I removed the three flathead screws, I was met with this!
May I ask:
Q: How do I test this thermostat to see if it's actually working?