In homes with forced-air heat, indoor air becomes very dry without a duct-mounted humidifier, so they're a pretty common accessory with minimal but important maintenance needs.  Most homeowners know that the humidifier water panel needs to be replaced every heating season.  But what happens if you forget to replace the water panel?

We recently found out.  I went down into the basement to get some tools and noticed water on the floor near the basement air handler.  Since it hadn’t rained recently (and our basement doesn’t get wet from rainstorms) I figured that something had to be going on with the humidifier waste pump, humidifier itself or (worst case) the air handler’s heating coil which passes air over a hot water coil from the boiler.

A little snooping around showed me that the bottom of the air handler ductwork was wet, so I could confirm that no water was coming in from outside the house.  Then, looking over the waste pump, it was clear that the exterior of the housing and wall of the duct it is mounted onto were dry.  That left the humidifier as my main suspect (and me hoping it wasn't the heating coil, the last and most expensive item on the suspect list).

I remembered that I hadn’t changed the humidifier water panel this heating season, so I removed the cover from the unit and found that the water panel had a lot of corrosion, and when removed, could see that the drain at the bottom of the water panel housing was indeed clogged.  This allowed water to cascade out behind the unit, down the ductwork and onto the floor.

I removed the entire water panel frame by taking the supply hose out of the top, threw out the old water panel and brought the frame to the sink.  A little warm water and scrubbing with a nylon brush got most of the residue off the frame, and the drain was completely clear.  I popped a new water panel into the frame and reassembled the humidifier (this took all of about 10 minutes, beginning to end).

The moral of the story?  Pay attention to annual maintenance requirements of your home’s operational systems and you’ll have a lot fewer headaches to deal with (not to mention water to wet-vac up off the basement floor).  If this had happened in the upstairs air handler, it would have been a real mess, with potential damage to the ceiling, walls and anything that got wet as a result.  Water panels cost less than $15, so this is a relatively inexpensive preventative maintenance item that will keep your home more comfortable, and if your air handler and humidifier are above living space, eliminate a nasty financial surprise if your humidifier drain clogs.