You had one job.
When a homeowner or an HVAC technician orders a furnace and installs it, they tend to expect that it was manufactured according to industry standards. It’s probably safe, functional and will serve its new owner for at least 15 years, depending on the model and how well it’s maintained.
Imagine, then, that several years down the line, a certified home inspector notices that something is just not right. It looks like a furnace, it’s installed like a furnace and it goes through its paces like a furnace. But it’s upside down.
That scenario is rare, but it’s documented. What’s the cause and what should the homeowner do? Read on.
Certain Carrier Furnaces Have a Known Defect
The case of the upside-down furnace has nothing to do with poor installation. It isn’t really upside down, at least not on the inside. Between 1992 and 2000, the Carrier company had a furnace assembly problem.
It was probably easier to make this mistake than it sounds. According to the ASHI the theory is fairly simple.
During the manufacturing period in question, certain upflow and downflow furnaces made by Carrier had the same dimensions. That meant the housing components for one would fit the other by rearranging the order of the panels.
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A little dirt is normal; a lot of dirt is not.
When the Cover is All Wrong, Nothing is All right
Louvered sections in a furnace housing are designed to let the burners breathe. The solid, airtight portion of the cover is designed to close off the blower cabinet. When they’re reversed, the furnace can’t perform like it should.
Experts say that in their experience, the first problem is “an extremely dirty system, since the blower cabinet pulls in unfiltered air.” A more dangerous problem is carbon monoxide. Another furnace they inspected with the same housing defect showed elevated levels of CO that increased when the blower was in operation. That’s not a benign problem; that’s a serious one.
Experts suggest that it all boiled down to cost savings for the Carrier company. They never intended for louvered sections to cover the blower and an airtight cabinet to cover the burners. But because the dimensions were identical, it was probably easy to make the mistake.
A furnace may appear to function normally even if the covers are installed upside down. The homeowner may have used it for years without realizing that there was a problem. Chances are, it wasn’t as efficient as it could have been when new. And as the years progressed, the additional strain of dirt buildup and poor ventilation likely reduced its efficiency much more quickly than another furnace with the same make and model. A history of repairs is likely. But it does make a home inspector wonder why no technician caught the problem before.
Fortunately, most Carrier furnaces built between 1992 and 2000 are fine. The easiest way to know if the one in front of you has a problem is to open it up and look inside. If the blower has a louvered cover, the homeowner has a problem.
There seems to be no end to the types of defects you’ll find on the job. A great home inspection reporting app makes documenting them easier. If you’re ready to upgrade to a better app that’s easy to use, Report Form Pro is the answer. Download the home inspection app for Android or get it for your iPhone or iPad at the App Store.