Not too long ago, Retta and I began hearing an unusual noise emanating from the air conditioning duct work.  I went down into the basement utility room to investigate the source of the noise.  It soon became apparent that the noise was coming from the 5 ton air handling unit (pictured below) that is a part of the heat pump system that cools and heats our home.  Inside the housing (on the left side of the picture) there is a large blower unit, which utilizes a fan assembly that looks much like a giant hamster exercise wheel.  The sound seemed to be originating from inside this blower, so I decided to call the company that installed this HVAC system for us a few years ago.  Last week, the company sent a repair technician, who pulled the blower assembly apart and determined that a broken fan unit was causing the noise.

Today the repair technician returned with the new parts, and after installing the new blower assembly, we were pleased to find that the offending noise had disappeared.  The technician then decided to test the unit under load, so we switched on the heat pump so that he could check the voltage and amperage draw.  He found that one of the two sets of auxiliary heating coils was drawing current, but that the other remaining set was not (both sets should have drawn the same amperage).

The technician proceeded to disassemble the unit again, this time to inspect the auxiliary heating coils, which are located at the rear of the air handler cabinet, above the blower unit.  He said something to me, which I could barely hear, because his head and shoulders were buried inside the air handler cabinet.  He said “there’s something I didn’t expect to find in here.”

And this is what he pulled off of one of the auxiliary heater coils - 

It just goes to show – when you live out in the country, there are frequently critters showing up where you least expect them, so keep you eyes peeled and be on the lookout at all times!