How to Replace a Sump Pump

About: We're just two dudes who make stuff. Sometimes it's with a CNC, sometimes it's DIY projects for the home. Other times, we cook great food!

Changing a sump pump is an easy enough task that any homeowner can accomplish.Having a plumber do the work for you can cost up to $500. I did mine for under $150.

My old sump pump was over 35 years old. It was old enough that the float had rusted off and I had to manually flush it. I also didn't like how the piping and unit was plumbed. We are remodeling our basement and the old piping stuck out 20 inches from the wall. Wanting to reclaim that space for some utility cabinets, it was a perfect time to replace that old unit.

About Sump Pumps:

Sump pumps come in a couple of different varieties. You can get them in submersible or pedestal styles.

My old unit was a pedestal style with the main positive features being that they are cheaper and last a really long time (35+ years for mine). In fact, I could have repaired the old one and it probably would have kept working for years to come. Their drawbacks are that they take up space above the floor which could be otherwise used and they are loud.

My new unit is a submersible style. They cost more and die sooner (10-15 year lifespan typically) but are more quiet.

(As with anything of this nature, I want to point out that I'm not a plumber so I cannot guarantee the accuracy of this work. It may or may not be up to code check your local ordinances)

Supplies:

Sump Pump - I am using a Wayne 3/4 CDU980E which is one of the best on the market

Check Valve - I am using my old valve

ABS Glue

90-degree long elbow - 1

45-degree elbow - 4

1 1/2" male threaded end - 1

5' 1-1/2" ABS pipe

Teflon Tape

Hacksaw

Screwdriver

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Step 1: Attach the Male Threaded Piece

This is a simple step. Wrap your threads in tape. If you wrap them in a counter-clockwise fashion, the tape tends to stay in place when you go to screw it into the fitting.

Screw it into the sump pump's fitting. DO NOT OVER TIGHTEN - these are cheap plastic and can break if you use a pipe wrench or channel locks.

Step 2: Glue Your Pipe in Place

Add ABS glue to both the fitting and the pipe.

Some will say to do this step before you put the male end int to the sump pump, they're probably correct. However, doing that will force you to wait 15 minutes or more before connecting the male end to the sump pump in order to let the glue fully dry. It's not a big deal either way you go.

Step 3: Remove the Old Sump Pump

Grab a towel because you're probably going to get wet.

Start by taking off the old check valve. The check valve's job is to keep water from going back down the sump pipe and creating a siphon (if there is a backup in your septic tank) or a drain directly into your basement if the outlet pipe is backed up.

That also means that there is going to be an 8 ft column of water that is going to dump when you disconnect the valve. Be prepared for it and known that it may smell awful.

Check valves come in all sorts of varieties. Mine simply had four pipe clamps that needed to be loosened before the unit would come apart into its three sections.

Once that is done, pull the old pump out.

Step 4: Start Plumbing - If Needed

This step is somewhat optional. As I said, I wanted to reclaim some of this space. Ideally, your pipe should go straight up and make as gradual of turns as possible. Mine won't be doing that.

Start by marking and cutting your outlet pipe about one inch below the top of the sump pit. Then, attach your first 45-degree elbow.

Step 5: Measure, Cut, Connect

Continue measuring, cutting, and connecting your pieces until you get to the wall.

Step 6: Install Your Check Valve

As I said, I will be using my old valve.

Install your check valve low in the system, closer to the pump than the ceiling. That way, once the pump shuts off, the water in the pipe won't refill the pit enough to turn the pump on when it flows back into the pit. That would cause your pump to turn on and off constantly.

Ensure that the valve is installed so that the water flow can go up but not come back down.

Step 7: Continue Plumbing

At this point, you should connect your outlet pipe to the main drain line. Measure, cut, connect until you get there.

Step 8: Finish!

Plug in your sump pump and test the unit. To test it, simply fill your pit with water. The unit should turn on and evacuate the water.

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    2 Discussions

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    TwoDudesMakingStufftytower

    Reply 24 days ago

    The most water comes from my central A/C unit. I also have a humidifier on my furnace, dehumidifier, water softener, and the occasional flood (until I fix my down spouts). It empties two to three times per day during the summer and maybe once per day during the winter.