Home Fix: Dwight Barnett answers home-improvement questions. This week's topic is on sump pumps.
Q: My house is surrounded by wetlands and ferns. We have a constant influx of water coming through our drain tiles and into the sump pump due to a high water table or spring nearby. Our sump pump has done an excellent job of keeping our basement dry.
My sump pump begins pumping after 6 inches of water has entered the pit, resulting in frequent on/off cycles. My neighbor’s sump is set so the water levels off at a certain point and the drain tile leading into the pit ends up being halfway submerged, resulting in much less frequent on/off cycles. Which setup is correct?
A: The Zoeller submersible pumps I reviewed have a float switch that automatically turns the pump on when the water level in the pit reaches anywhere from 7 ½ to 9 ½ inches depending on the horsepower rating of the pump. The pump then shuts off automatically when the water level recedes to approximately 3 inches.
You could elevate the pump by placing it on a concrete block, but this would leave a lot of water in the bottom of the pit that could become a health issue as the water stagnates and evaporates.
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No matter what you do, the pump will come on when the float reaches a set point on the pump housing and will go off when it reaches the bottom limit on the pump housing.
The motor is really not designed to operate on short cycles, so any adjustments you can do would be helpful.
You need to compare the model number and accessories of the neighbor’s pump with your pump. The difference might be the horsepower of the pump used, the volume of water pumped per minute and how high the pump has to lift the water to the exterior.
I would encourage any homeowner who has a basement sump pump to have a backup or emergency system, such as a battery unit, to protect the home during power outages.
I prefer a backup pump operated by water pressure provided by the home’s water-supply pipes unless the home is supplied by a well, which also is dependent on the power supply.
A battery backup system, even if it is well-maintained, can fail, and the battery backup has a limited amount of run time, whereas the municipal water pressure will be there to siphon the sump pit even when the power is off.
One thing you did not mention is the backflow preventer valve or check valve. The check valve allows water to flow in one direction only and it should be placed as close to the pump as possible.
Without a valve, the water that is in the pump’s drainpipe will flow back to the sump pit the second the pump shuts off. This can result in the quick on and off cycles of the pump similar to what you are experiencing.
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.