How to Change a Sewer-Line Basement Sump Pump

Symptoms of a Problem

• The first indication that your sewer sump may have a problem is likely to appear as backed up sewage in a basement shower, tub or commode. When the pump motor is not working, the sewage has no way of getting to the main sewer line, so it will back up in the basement fixtures.

Before Replacing the Pump

• Sewer sumps are pricey, so it pays to make sure the pump is the source of the problem before buying a new one. Go down to the basement and listen to see if the pump motor is running. A clog in your home’s main sewer line can prevent the pump from pumping the waste into the line. If this is the case, the pump will cycle repeatedly as it attempts to empty the collection bucket. Check the electricity that runs to the pump. Many pumps wire directly into the home’s electrical panel, and if the breaker flips, the pump stops working.

Pump and Tank Properties

• Two pipes and an electrical wire extend from the top of the collection tank. The lid on the tank has an airtight seal, and there are individual seals around the two pipes that extend upward. Because the tank contains sewage and sewer gasses, the seals are essential. Beneath the lid, the two pipes and the wire all connect to the actual pump. One pipe carries liquefied waste to the main sewer line and the other pipe ties into the home’s ventilation stack.

Pump Removal

• Turn off electricity to the pump. If the pump lid’s been in place for many years, which is often the case, you can apply gasket soap or regular dishwashing soap to the two pipes that extend out of the lid to make removal easier. Above the lid, you’ll find two plumbing fittings that connect the pipes coming from the pump to the pipes above. After loosening these fittings with a wrench, slide the lid up and off the two pipes, which will remain connected to the old pump. The old wire may pull off in the process. If not, remove the wire after the pump is out. Using the pipes as handles, you can lift the old pump out of the tank and place it in a large plastic trashcan for disposal.

New Tank Installation

• Before lowering the new pump into the tank, attach new pipes to the new pump and insert the pipes through the tank lid, using gasket soap if necessary to make them slide freely. Run the wire through the designated hole in the lid and connect it to the pump. Now you can lower the new pump into the collection tank, slide the lid down over the pipes and connect the pipes to the matching drain and vent pipes to which the old pipes were connected.