Sump pumps are installed in some homes to help pipe surface water, ground water, melting ice and snow. Pumps are also used to pipe away ground water from the area under the basement floor slab and around the basement foundation walls. Exterior perimeter drain systems should not be directed into the sump pumps because the water can flood the home if there is a malfunction or a pump discharge pipe obstruction.
Some houses need sump pumps because the exterior slope of the soil allows snow, water and ice to collect around the exterior walls of the home. In some areas the water table is high and pumps are used to help avoid water infiltration into the lower level of the home.
Most sump pump systems are comprised of a pit (tank) that is located below the basement floor slab and a pump and discharge line. The pump has an inlet hole or may have multiple inlet holes and can be made of various materials. Most pump pits are either plastic, metal, or cement.
The actual pump is located inside the sump pit. The pump may be a pedestal style with the electric motor located above the pump. The pump may also be a submersible style pump with the motor and the pump located at the bottom of the sump. In both styles of pumps there will be a 120 volt electrical power line and a float switch to activate the pump as the water level inside the sump pit rises. Sump pumps can be powered by an ordinary electrical receptacle and at other times be powered by direct wiring to the pump motor.
There is a discharge pipe from the pump that pipes the water out of the sump pit when the pump engages. The discharge pipe is often plastic pipe. There is no need for a vent pipe on a sump pump because the top of the pit is not tightly sealed. Sewer odors are also not an issue because the pump is discharging ground water and not waste water from plumbing fixtures.
Discharge pipes from sump pumps that are installed on the exterior of the home are often buried just slightly below grade. This pipe must be sloped down from the home so water will effectively drain out of the pipe. If water freezes it may block and obstruct the discharge pipe.
Caution must be taken when a pump is tested. There is an inherent electric shock hazard because there is water and electricity in the same proximity. Use a wooden stick to lift the float to test the pump. Never use your hand to lift the float switch because if there is a short you may get an electric shock. Although not required it is beneficial to have a GFCI protected electrical receptacle supply power to the pump. Sump pumps should not be operated with out water. Before the pump is tested make sure that there is water in the bottom of the sump pump. You can always pour a few inches of water in the sump pit to allow you to test the pump.
When inspecting your sump pump, you should also view and inspect the discharge pipe and make sure the line is not obstructed and is discharging freely. If the discharge pipe is obstructed the water level in the pit may raise too far and then flood the basement.
If excess noise or vibration is heard it may be an indication that the pump motor or the bearings are worn. Worn bearings may be caused by the lack of proper maintenance. Replacement is recommended in order to make sure the pump will operate when it has too.
Some other common sump pump problems are:
Short cycling or operating continuously. This condition may be caused by a sticking float switch or debris inside the sump pit. The sump can become damaged. Often metal sump pits rust and corrode. Plastic pits can be damaged by soil pressure. All sump pump pits should have a securely fitting lid in order to avoid possible injury.
It is a very good idea to keep a back-up sump pump on hand so that the existing can be quickly changed if there is a malfunction. It is also very desirable to have a battery back up to power the pump in the event that the power should fail.
