The sump pump discharges water out of its service area into the yard or other drainage field. After a heavy rain, it may run for several days, so even if your basement is dry, that may be because the sump pump is doing its job. If your area has not had substantial rainfall for a while, then something is malfunctioning in the sump pump or related apparatus. Leaking water pipes may be the culprit. Listen to the pipes at the juncture where they enter the building. If you hear a leak, call a plumber.
A constantly running sump pump may be too small for the service area. Not only does it use more electricity, but it will burn out faster than a sump pump of the correct size. If the sump pump is too small, your only alternative is replacing it with a larger model adequately sized for the task.
Even if the sump pump is the right size, an inadequately sized liner causes the pump to run continuously. This causes the sump pump to eject water out of the house more quickly than the liner fills. The pump then keeps turning on and off, a process called short-cycling. The constant use wears out the sump pump's mechanical elements much faster than normal, as well as uses more electricity. Replacing the liner with a larger one is the only option.
Extend Discharge Area
The sump pump may be discharging too close to the building, and the water soaks back down into the ground around the foundation. Direct the water discharging from the sump pump farther away from the structure. Also, extend the building's downspouts so water from this source discharges farther away from the foundation. If the ground slopes toward the foundation, you may need to regrade it. If your building has downspouts discharging directly into building drains, reroute them at least 6 feet away from the foundation.