This is a real-life story.  A couple, renting a house at a lake, were awakened in the middle of the night by a loud, unfamiliar nose. Earlier that day a carbon monoxide alarm had been activated and it now screamed a warning.  Concerned, they called 911.  An emergency crew arrived quickly and took measurements.  The CO level in the home was significantly elevated.  The couple remained in the home that night, but spent it with windows wide open and endured a windchill in the low 20s.

Two things happened the next day.  One of the residents went for medical check.  Her blood test revealed the presence of carbon monoxide, but it was not high enough to be life threatening.  The landlord also acted quickly.  He had the furnace replaced the same day.  As the old unit was hauled out, the problem became obvious. The heat exchanger of the 20-year old unit had tiny holes in it.

What are the takeaways from this couple’s brush with danger?  Mechanical Extremes’ Harold Wilkes says a tune up would have detected the problem.  And that is all the more relevant as furnaces age.  “Most people understand that when a furnace reaches 20, it’s time to review if it should be replaced.”  The other lesson?  If the CO alarm had not been activated and the problem festered, where would that couple be today?

Furnaces operating properly are a blessing—they keep you cozy and warm during Michigan’s cold months.  But that warmth comes from a flame contained within the unit.  A byproduct of the combustion is an odorless gas.  It’s only deadly if it collects in closed spaces, and is breathed by people and their pets.

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