Read This First: Fix the Root Leak Before You Replumb

Before you touch a saw or glue, one rule matters more than any step in this guide:

Do not replumb the pump if your pool is still actively leaking and running low on water.

If a leak in the pool is causing the water to drop and the skimmer to suck air, that air is what overheats and cooks your plumbing. Fix the equipment without addressing the leak, and you can end up right back where you started.

If you’re not sure whether you have a real leak, start here:

• How to Run a Pool Leak Bucket Test
• Pump Sucking Air? Why That Little Leak at the Pump Points to a Bigger Problem
• Why You Shouldn’t Replumb the Pump Until the Leak Is Fixed

Tools and Parts You’ll Need

Most pump pads use 1½” or 2″ PVC on the suction and return side. You’ll need to match whatever you already have.

Basic Tools

• PVC cutter or fine-tooth hacksaw
• Measuring tape
• Marker (Sharpie or similar)
• Rag or old towel
• Safety glasses

Parts & Supplies

• 1½” or 2″ PVC pipe (same size as existing pad)
• Matching PVC unions (suction and/or return, as needed)
• Couplings or 45°/90° elbows if needed to line up
• PVC primer and PVC cement suitable for pool plumbing
• Thread sealant or Teflon tape if using threaded unions (as applicable)

If you’re not sure which size you have, we’ll show you how to check next.

Step 1: Confirm Pipe Size (1½” vs 2″)

To most people, all white PVC looks the same at first. In reality, most residential pads are either 1½” or 2″.

Simple ways to check:

• Look for writing on the pipe (it often says “1½" SCH 40” or “2" SCH 40”).
• Measure the outside diameter with a tape measure:
  • 1½” pipe is about 1.9″ OD (outside diameter).
  • 2″ pipe is about 2.375″ OD.
• If you’re still unsure, take a clear photo and a short video with a tape measure and show it to a pro or in a pool forum.

Once you know your size, only buy unions, couplers, and pipe that match.

Step 2: Identify Exactly Where the Leak Is

Dry the area around the pump completely with a rag, then:

• Turn the pump on and watch the suction-side union (pipe going into the pump).
• Watch the return-side union (pipe coming out of the pump).
• Look for drips, slow seeps, or water collecting around any joint or fitting.

Try to answer:

• Is the leak at:
  • The union nut and o-ring?
  • A glued joint/coupler?
  • A crack in the pipe itself?
• Is there enough straight pipe on either side of the leak to cut and glue in a new piece cleanly?

If the leak appears to be coming from a crack in the pump housing instead of the fittings, stop here and read:
Do You Really Need a New Pump or Just a Replumb?

Step 3: Plan Your Cuts and Dry-Fit Everything

Before you touch the glue:

• Shut off power to the pump at the breaker.
• Close valves as needed and drain water from the lines so you’re not cutting into a full pipe.

Then:

• Mark the pipe where you will cut to remove the leaking section.
• Think through how you’ll reconnect:
  • Do you need couplers on each side?
  • Can you shift the pump slightly if needed to line things up?
• After cutting, dry-fit all new parts:
  • Slide unions and couplers into place without glue.
  • Make sure everything lines up without forcing or twisting.

If you can’t get a clean, relaxed fit without a ton of strain, it may be time to call a repair tech instead of fighting it.

Step 4: Glue the New Plumbing

Once you’re confident in the layout:

1. Clean the ends of all pipes and fittings with a rag.
2. Apply PVC primer to both the pipe and the inside of the fitting.
3. Apply PVC cement to both, then push the pipe into the fitting with a quarter-turn twist.
4. Hold for several seconds until it grabs; don’t let it push back out.
5. Repeat for each connection, working methodically from one end to the other.

Follow the cure time on your PVC cement. Many products want at least 15–30 minutes before low-pressure testing and longer before full pressure. In cooler or very humid weather, give it extra time.

Step 5: Restart and Check for Leaks

When the glue has cured:

• Open any valves you closed.
• Restore power at the breaker.
• Prime the pump (if needed) and start it.

Watch the new plumbing closely:

• Look for drips at every joint and union.
• Check for air in the pump basket after it’s been running a few minutes.
• Listen for gurgling at the skimmer (if you hear it, your water may still be getting too low).

If everything is dry and the system stays fully primed, you’ve likely solved the pump-side leak.

When to Stop and Call a Pro Instead

Even handy homeowners have a limit. It’s a smart move to call a repair tech when:

• Your equipment pad is cramped and crowded, and a small mis-cut turns into a major rebuild.
• You discover cracks in the pump housing or suspect the pump is near the end of its life.
• You’re not confident that the pool leak situation is actually under control yet.

In those cases, it’s better to pay for one clean, professional fix than to chase multiple DIY attempts.

For help deciding who you really need, see:
Leak Detection vs Equipment Repair vs Pool Service: Who to Call for What