my mom always used to say, “if you didn’t learn anything new today, you’ve wasted your day!”
well, friday was far from wasted!
i slept really well thursday night. almost too well. not like “i took something” kinda well, but really close. typically this happens for one of two reasons – pure exhaustion, or cooler temps in the house. yep – let this house drop down to around 65° and i pass daphuk out.
that doesn’t happen anymore because i have a wife and, typically, women get cold a hell of a lot easier than i do.
but it turns out there were special circumstances – she tried to get the heater started, which is usually set at 68° but it would start to kick on and stop. likewise, i tried to start it up and it was no go. so we called in a repair guy, and when he got out here he taught me how to diagnose shit myself on this unit, and what the current code meant (pressure switch error).
a brief lesson – when you turn on a modern gas furnace, before the gas will actually kick on, the exhaust fan kicks on and start to blow air up the chimney. this creates a vacuum in the pressure switch housing, triggering the gas to kick on. why all these steps? because if the pressure switch doesn’t detect a vacuum it means something is blocking the chimney and all the gas fumes don’t have anywhere to go, so they’ll fill the cabinet, combust, and blow your house to hell.
that is, what they call in the heating & a/c biz, “bad”.
so he showed me where the error light is located and the chart to read the sequence showing it was pressure switch. turns out i’d removed and replaced said switch when i removed and replaced said exhaust blower last year (and, according to him, done the whole job perfectly). he then took the vacuum hose off the blower and sucked on it and you heard the pressure switch click, indicating the switch wasn’t the issue, something was blocking the exhaust.
first step was to pull the chimney off the unit, and right there at the top of the blower i installed was this:
a little bird had fallen to its demise down the exhaust stack and gotten wedged in the smallest part of the opening. no blood, no decay, so it had obviously gone somewhat both peacefully and recently. we plucked it out, bagged and trashed it, and everything roared to life just in time for some chilly nights this past weekend.
straight service call charge – $69.99
knowing how to diagnose the problem myself next time – priceless.