Home Fix: Dwight Barnett answers home-improvement questions. This week's topic is about condensate water damage from an air conditioner.
Q: I have a combination furnace/air conditioner in a utility room of my finished basement. The air conditioner has a pump near the bottom of the furnace that collects the condensate water from the air conditioner and pumps it across the basement to the laundry drain.
I failed to notice that the pump had stopped working and the condensate water flooded to the finished basement, causing a lot of damage.
The repairman said he can install an alarm that will let us know if the pump fails again, but that wouldn’t help if we were not home to hear the alarm. Any ideas would be appreciated.
A: The air conditioner not only cools the home, it also dehumidifies, removing moisture from the air. Most units drain to a dedicated sewer or drain, but in some cases, such as yours, the furnace is below the sewer and the water has to be pumped to a higher level.
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Most condensate lift pumps have a float inside the water reservoir that turns the pump on as the water rises. Depending on the size of the air conditioner and the amount of humidity in the air, the lift pump will have to handle anywhere from five to 20 gallons of water a day.
That much water can do a lot of damage trapped inside a basement, but in homes with a furnace/AC on the second floor, you cannot imagine the amount of damage that much water can do.
When a furnace/AC is located above a finished area of a home, it is necessary to place a catch pan under the furnace in case of a condensate leak.
A number of the homes I have inspected do have catch pans, but there are either no drainpipes connected to the pans or the pipes are draining to a sewer somewhere out of sight and the homeowner is unaware if a leak occurs in the furnace/AC.
There are float switches available that can be installed inside a catch pan that will shut the AC off if water collects in the pan. There also are float-switch sensors for a condensate lift pump that will sound an alarm, and if too much water collects, the switch will turn your AC off.
When the AC is off and the house gets hot, you’ll know you have a problem.
A simple Web search turned up www.floodmaster.com/home-water-leak-detection-shutoff.php with photos of damage that can be caused by a water leak and information on alarms and AC shutoff switches.
You could make your own system by having the repairman set the basement condensate pump in any type of catch pan and then add a float switch to shut off the air conditioner if flooding occurs.
Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home-improvement questions at d.Barnett@insightbb.com. Sorry, no personal replies. Always consult local contractors and codes.