How to Replace a Septic Tank Pump

Septic tank lids uncovered in the ground
  • 2-4 hours
  • Intermediate
  • 450-3,000
What You'll Need
New grinder pump
Wire twister
What You'll Need
New grinder pump
Wire twister

Septic alarms indicate when the septic tank pump is not operating. There are several pumps used in a septic tank. A septic tank system will always have a grinder pump. The grinder pump is used to grind all the waste from the house into smaller pieces that can be broken down by the bacteria in the septic tank. There may be a riser pump installed also in the septic system if it lies on a hill or if the drain field is located above the septic tank.

If any of these pumps fail, the septic tank system is no longer operational. The pump must be replaced promptly to prevent overflow or drainage issues. Here are the steps to replace a septic tank pump.

Step 1 - Identify Pump to Be Replaced

If the waste pieces are not being broken down into smaller pieces, the pipes in the drain field will become clogged. This may result in sewage backup up in the basement of the house or having toilets backed up and slow to drain. If this is happening then the grinder pump needs to be replaced. The riser pump moves the waste from the septic tank into the drain field. If waste is not being carried to the drain field, the riser pump is broken. The pump gets its name because it “raises” the waste to the higher drain field.

Step 2 - Purchase the Correct Pump

sewage drain field

Besides the grinder pump and the riser pump, there is also a sump pump. Do not confuse the sump pump with the correct pump that you need to purchase. A grinder pump will have an internal wheel that will grind the waste as it passes through it. A riser pump will push the waste through the pipes to the higher level. Make sure that you purchase the correct pump.

Step 3 - Remove Broken Pump

Most grinder pumps are located in the basement of a house connected to the drain pipe that flows into the septic tank system. The pump will have electrical wiring attached to it. The electrical wiring will need to be disconnected before you can install the new pump. It is recommended to disable the electricity at the electrical panel before removing the wiring.

Step 4 - Install Alarm System

grinder pump

Any new grinder pump is required to have an alarm system with it. This alarm is required by city and county sewer codes. The alarm will sound if there is a problem with the level of wastewater in the septic tank, which alerts the homeowner to a potential problem with the septic system. The alarm will be required to be installed on a separate breaker system from the pump. It may be necessary to run new electrical wires for the alarm system to the electrical panel and install a new breaker. Local building codes may require an inspector to inspect the installation of any new electrical wires.

Step 5 - Install New Pump

The new pump will require its own electrical system. The new pump should be connected to the electrical system where the faulty pump wiring was removed. Although not recommended, you can install waterproofing around the new pump to protect it from water. Once the new pump is installed the septic tank system will be operational.