Today, after several 12 hour days behind the wheel and in front of furnaces, business slowed to a trickle. I had one clean and check on a Carrier 80% unit in Dewitt today. That was my one and only call besides helping my boss with a unit heater in the garage. While the furnace itself had the usual signs of neglect (A very dirty flame rod and a hot surface ignitor ready to fail) the humidifier was a sight to behold. Because of privacy concerns, I didn't take a picture of said humidifier, but it was the worst case of mildew I've seen in several years. This was a General Filters model 1099. the big one with the clips holding the top and bottom to the chassis. This whole chassis was black with mildew, the steel frame on the pad was rusted and the aluminum substrate also had a mask of black fungi. Take my word for it, this was gross.
Because there was a fair amount of luggage nearby and this was a finished basement with carpeting throughout, I elected not to use bleach to clean the chassis out. Instead, I opted to use evaporator coil cleaner with a spray bottle and some elbow grease to get this muck out; not easy with a General. This humidifier fills through the top plate and drains excess water through the bottom. Since this is a bypass humidifier, using a pipe from the opposite duct, there is no fan to move the air through. It uses the furnace fan to move the air through the wet pad and substrate. The excess water drains through a hole and a tube in the bottom plate.
The problem was the pad had not been changed in five years and material and dirt had clogged the drain. This water stagnated and caused the interior of the chassis to remain wet. Because the coating designed to keep biological activity to a minimum on the pad was long gone, the mildew situation intensified; it had all the makings of the perfect storm. Months of no maintenance dumped more dirt into the drain and created more mildew. This in turn created more material to plug things up. The result could have been a nightmare for the homeowner because the drain could have failed completely and the water would have had nowhere to go but over the edge of the plate and onto the floor and into the furnace. This water would have ruined drywall, carpeting, furniture and that expensive luggage inched from the furnace. It could have also caused issues with rusting the duct work.
But the worst of the worst is air quality. Mildew or mold isn't fun to breathe, nor does it help the quality of furnishings in a home. The toxins released by this stuff can sicken people, especially if they have allergies (the homeowner does). The pad was about $50 installed and included expert installation, which is another caveat that homeowners need to understand. Just because they can buy something in the store doesn't make them qualified to install it. I've seen more than a few bungled humidifier pad installs to know that these are not idiot proof, including one rather talented homeowner who elected to put a #10 Aprilaire pad into a Model 550 humidifier. This one resulted in a three inch gap that's going to let gallons of water ruin his drop elbow and furnace when the pad (an aftermarket knock off) finally collapses in a heap.
My advice is to call a professional to get this work done the right way. Make sure he or she is bonded and has some training, but the most important thing is to make sure this person gives a damn about the job they are doing. You would think that as a homeowner, you'd know and care more than the guy who does does this for a living every day.However, this isn't the case. I've had thousands of dollars in training and have hundreds of dollars of tools and equipment to help make sure the job is done right. I've also worked on more humidifiers in one week than most laypeople will do in 50 years.
Other technicians will probably have similar stories too, but the message is clear. Some things are better left to a professional, and need to be done. Maranatha!