Replacement Pool Pump Installation
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how to replace your pool pumpIf your pool pump is screaming like it’s on its last legs, or maybe it’s given up the ghost altogether, here’s how you can replace your own pool pump, and restore some peace and quiet to your backyard oasis.

If you can handle some light plumbing and some lighter electrical, you should be able to install your own pool pump.

Let’s start with a materials list, to install a new pool pump, gather these items:

  1. Replacement pool pump
  2. PVC fittings and pipe
  3. Hacksaw or PVC saw
  4. PVC glue and PVC primer
  5. Teflon tape or similar thread sealant
  6. Measuring tape
  7. Screwdrivers & Pliers

Step 1 to replacing your pool pump is to remove the old one, silly!
Remove the Old Pool Pump.

First, we want to cut the pipe that comes into Ugly Pool Pumpthe old pump. Look for a place to cut the pipe that will leave at least 1.5″ of free or exposed pipe that is not covered by a coupling or other fitting. This will allow you some pipe to connect the new pump plumbing fittings.

In some cases, the suction line valves or check valve have been installed so closely, that there is no room to cut without sacrificing one or more valves. If you can’t find a place to cut that will leave at least 1 inch of exposed pipe to connect to, you will need to go further back along the pipe, and rebuild it back to the pump from this point.

Second cut that we make is on the effluent side of the pump, or the pipe in between the pump and the filter. Here again, find a spot that is close to the pump, and where cutting it will leave 1-2″ of open pipe that you can connect to. If you are reconnecting the exact same pump, leave at least 1 inch on both sides of your cut, so that you can use the same pipes and just reconnect with two PVC couplings or unions.

Once the incoming and outgoing pipes are cut, use large channel lock type pliers to remove the threaded pipe fittings out of both ends of the pump.

Our next step is to remove the wiring that comes into the back of the pump. Before opening up the back, open up the sub-panel breaker box and shut off all of the breakers, and make sure the power is off to the pump.

Remove the rear cover plate and you will find 3 wires coming in the back (4 for two-speed motors). Use a flat head screwdriver to loosen the terminals and pull the wire out from underneath the large screw head, or if your wires are connected using electrical connectors, use needle nose pliers to remove the terminal connectors, shown right.

90 degree conduit fittingAfter the wires are loose, we need to disconnect the conduit from the conduit fitting. In most cases, you’ll find a 90 degree steel fitting which brings the wires into the back of the motor. Locate the nut that holds the flexible conduit into the fitting. After fully loosening this nut, pull the flexible conduit gently, to pull it – and the wires, our of the fitting and free from the pump.

Unless your pump has been bolted down to the equipment pad, you should now be able to remove the old pump and place it out of the way. You’re done with step 1!

Step 2 to installing a new pool pump is to wire up the new pump
Wire up the New Pool Pump.

It’s easier to wire up the pump first, before you plumb in the new pump. I like to stand the new pump up on it’s nose and take a seat for this part. If you haven’t already, remove the conduit fitting from the old pump and thread it into the threaded port on the same side of your new pump. Then gently feed the wires through the fitting and loosely tighten the nut to seat the conduit into the fitting.

Your new pump will come wired to accept 230V. This is what most inground pool pumps are running with. If your pump plugs into an outlet, or is connected to a single pole breaker, it most likely is using 115V. If unsure, use a test meter to verify voltage. To use 115V, follow the instruction tag or the Low Voltage wiring diagram on the motor. To switch your pump to accept 115V, you only need to make one or two minor wire changes on the terminal board.

No matter if you are wiring it 230V or 115V, there are 3 wires to connect, 2 power leads and one ground wire. The green ground wire will connect to the green screw that is up above the terminal board, shown pictured at right. Wrap the ground wire around the ground screw and tighten down firmly.

The other two wires, connect them underneath the large terminal screws orTerminal board for a pool pump motor use terminal connectors to slip over the spade terminals. It doesn’t matter which wire goes to which screw. Connect either one to terminals marked L1 and L2. Your terminal board may be white plastic, but the set-up will be the same.

If you have a fourth wire, connect this to the low speed terminal on the board. You will only have this fourth wire if you are wiring up a two-speed motor.

If you are replacing a single speed motor with a two-speed motor, you will need to buy a different time clock, and add the fourth wire. The Intermatic P1353 Digital Timeclock series will allow you the most flexibility in wiring up a new two-speed pool pump.

After the wiring is complete, screw on the cover plate and put away your screwdriver, you’re done with Step 2!

The third step in replacing your pool pump is to plumb in the new pump
Plumb in the New Pool Pump.

If your new pool pump came with unions, insert the o-rings in the groove and hand-tighten snugly. Position the replacement pool pump on the equipment pad to check how it lines up with the pipes that connected the old pump.

If you are using the same make/model as before, you should have no problems with the plumbing connection, as the pipes coming in and out of the pump should be the same distance from the new pump.

Replacement pumps may be taller or shorter than the previous pump – and you may have to get creative to make it work easily. If your new pump is shorter, use bricks to raise the pump to the proper level to that the incoming pipe lines up with the incoming port on the new pump. If your new pump is taller than the incoming pipes, you may have to use a few 45 degree fittings to bring the pipe into the pump at the right level. Some pumps have adjustable bases, this can be a real work-saver.

Once you have an idea of how to match the height of the incoming pipe, take a look at the outgoing pipe. Here is where some of your creativity may need to be harnessed to make slight adjustments in the direction of the piping, to make the simplest connection to the pipe going to the filter. Try to use as few fittings as possible, and you may find it easier to cut off more of the pipe, and replumb with new pipe and fittings, all the way, or most of the way to the filter.

This is also a good time to consider future serviceability of the pump and motor. If the rear of the motor backs into a wall, or if it’s very hard to reach the pump basket, could you reposition the pump for better access? Another improvement would be to raise the pump out of the dirt and mulch, and out of reach of any 100 year flood waters. Good ventilation is also important for electric pool pump motors.

When you have devised the ultimate plumbing plan, dry fit your pipe and connections before applying primer and glue. Here’s some other tips on proper pool plumbing.

  1. Measure twice, cut once.
  2. Use fresh PVC glue and primer.
  3. Prime, Glue and Connect within 15 seconds.
  4. Use a twisting motion when gluing.
  5. Hold glued connection together for 15 seconds.

For threaded fittings, if your new pump did not come with unions, you will need 2 Male Threaded Adapters (MTA) to thread into the incoming and outgoing ports of your new pump. Before threading in, squeeze out some Blue RTV silicone “Blue Goo” onto your finger and smear it into the threads of the fitting. Then wrap the threads completely, 3 times, with Teflon tape. Wrap the threads in a counter-clockwise direction so that the Teflon tape won’t peel back as you thread the fitting in a clockwise direction.

After you have connected the incoming pipe and the outgoing pipe, you have completed step 3! The only thing left to do now is to fill up the pump with water, open all the valves and test out your new replacement pool pump.

Enjoy the peace and quiet!


Davy Merino
InTheSwim Blog Editor


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