Q: What is a sump pump?
A: The basic function of a sump pump is to keep the level of surface water lower than the basement floor. In some cases sump pumps also are used to control the amount of water brought into the basement from the sewer backup

Occasionally sump pumps are installed in yards to control flooding conditions outside the home. Another type of sump pump is a grinder pump which is used in disposing of sanitary sewage.

In this article I will discuss the use of sump pumps to control surface water as a means of aiding in waterproofing your basement.

The main intent and the most common use of a sump pump is to discharge water out of the basement that the drain tile system (that lies under the basement floor) has carried to the sump pit.

Many cities and towns require sump pumps to be installed at the time the house is built and/or before it is sold. In previous years, the drainage system under the basement floor would discharge its water into the basement floor drain, which in turn would carry the water into the sanitary sewer. The growth in population and expansion of home building lead to an overload of the sanitary sewage system due to storm water and sewage in the same pipeline. These conditions prompted a change in the plumbing codes that resulted in the mandatory installation of sump pumps and the disconnecting of surface water drain tiles from the sanitary sewer.

At this point I should clarify the purpose of the drain tiles under the basement floor. The intent of this system is to pick up surface water that builds under the basement floor and around the foundation, and carry it to a discharge point, that is a floor drain or a sump pump.

In some cases sump pumps are installed next to basement floor drains that have a history of backing up. The intent is as the water backs out of the floor drain, it falls into the sump pit and the sump pump discharges the water outside. This is one way to control sewer back up but not necessarily the best way.

Sometimes the sewer will back up with a greater volume of water than the pump can handle, causing the pump to become overwhelmed and not effective. To correct this it would necessitate a high capacity pump that would handle any volume of water that the sewer could possibly put into the sump pit. The alternative to pumping sewer backups is to prevent them by installing a gate valve (a manual shut-off valve) in the main sewer line.

Q: How do I know what size sump pump I need?
A: What you need to consider is horsepower not size. The horsepower requirement for a house is determined by the area of drainage connected to the sump, the depth to the groundwater, the depth of the basement, and a few other factors. A 1/3 hp pump is standard for most houses.

Q: What is the most common reason for sump pump failure?
A: The leading cause for a sump pump to fail tends to be a switching problem. Sometimes the pump can shift inside the basin causing the float that operates the switch to lodge against its side. Debris can also be a factor; it can interfere with the action of the pump switch. It is important to make sure that your pump switch and float arm assembly move freely.

Q: Can the pump burn out if the outdoor pipe is frozen shut?
A: In that type of situation it will generally overheat if left in this condition. Almost all sump pump motors have thermal protection built in. The thermal relay will reset itself when turned off and allowed to cool down.

Q: How can I check my sump pump to see if it is working?
A: First you have to make sure your outlet pipe is not frozen shut or plugged and directs the water away from the house. Take a look inside by opening the lid (if it has one) and make sure it is clean inside and there is no debris causing the pump inlet to be plugged. Next, pour about five gallons of water into the sump and look for the on/off switch and listen to the pump. Make the switch turn on and off at least twice.