What Causes Hot Water in a Sump Pump?

Sump Pump Operation

Basic sump pump operation involves positioning the unit at some point below the floor line of a basement, or crawl space. From there, automatic sensors determine whether the water level requires the sump pump to turn on. Normally, a sump pump will turn on and off in intervals based on existing water levels. Any time a pump runs continuously, its motor components become hot. As water continues to circulate through the motor, it becomes hot as a result of the motor’s overheating. When a unit runs continuously -- whether water is present or not -- one or more components has malfunctioned.

Pump Capacity

Sump pump units come in different capacities in terms of how much water a pump can handle on an ongoing basis. In cases where the ground water level beneath a home exceeds a pump’s capacity to clear away excess, the unit may run continuously in an attempt to keep up with ground water levels. In effect, the sump pump cannot handle the job. As motor components are working nonstop, eventually the water that comes out of the pump will remain hot for as long as the pump runs. In some cases, raising the pump unit a couple inches will reduce its running time, since water levels must come up higher in order for the pump to turn on.

Check Valve

A sump pump uses a discharge pipe to send water up and out of a basement area. Discharge pipes should have a check valve located at the point where the pipe releases water to the outside. Check valve malfunctions -- or a missing check valve -- can result in excessive and ongoing sump pump operations. In effect, a missing or malfunctioning check valve means a certain amount of water will flow back down into the sump pump area. When this happens, the pump ends up recirculating the same water in addition any water that’s risen in the interim. Much like in the case of an overworked pump, the motor components get hot and so does the water.

Discharge Pipe

While a seemingly simple component, a faulty discharge pipe can hamper a sump pump’s ability to move excess water amounts. It’s not uncommon for sump pumps to circulate sand particles or dirt caught up in the water that runs through the pump. Over time, sand and dirt particles can clog up the discharge pipe and prevent water from flowing to the outside. As a result, water drops back down into the pump area. A loose or detached discharge pipe can bring about the same result. In addition to clogging the discharge pipe, sand and dirt particles can cause a sump pump’s impeller blades to corrode. Within each scenario, an over-worked motor turns cold water to hot water.