How to Prime Your Pool Pump: Complete Step-by-Step Guide

Tools & Supplies Needed

Understanding Pool Pump Priming

Priming your pool pump is essential after any maintenance that allows air to enter the system. When air gets trapped in the pump housing or suction lines, it prevents proper water circulation and can cause the pump to run dry, potentially leading to damage. The priming process removes this air and establishes proper water flow throughout your filtration system.

Pre-Priming Safety and Preparation

Always turn off power at the breaker before beginning any pump work. Never attempt to prime a pump while it's energized. Gather your tools and have a garden hose ready - you'll need water to fill the system.

Check that all suction-side valves are open, including skimmer and main drain valves if your system has them. Ensure the return valve is also fully open. Any closed valves will prevent proper priming and water circulation.

The Priming Process

Remove the pump lid by turning it counterclockwise. You'll likely need to break the seal, so expect some resistance. Once open, remove the pump basket and inspect it for debris - clean if necessary before proceeding.

Here's where many pool owners make a critical mistake: fill both the pump basket and the entire pump housing with water. Don't just add a little water - fill it completely until water reaches the top of the housing. This eliminates air pockets that could prevent proper priming.

Reinstall the clean pump basket, ensuring it sits properly in the housing. Replace the pump lid and hand-tighten it firmly. The lid needs to create a proper seal, but don't over-tighten as this can damage the threads or O-ring.

Starting and Monitoring the System

Turn the power back on and start your pump. You should hear the motor running, but initially, you might not see water flow immediately. Watch the pump housing sight glass or clear lid - you should see water and air bubbles churning as the system purges air from the lines.

Most pumps will establish prime within several minutes, though timing varies by system. You'll know it's working when you see steady water flow at the return jets and the pump basket fills completely with water. The churning and air bubbles in the housing should stop, replaced by clear, steady water flow.

Troubleshooting Common Priming Issues

If your pump doesn't prime after several minutes, turn it off and repeat the filling process. Sometimes air pockets in the suction lines require multiple attempts to clear completely. Avoid running a pump without prime for extended periods as this can damage the impeller and motor - consult your pump manual for specific limitations.

Check for air leaks in the suction side if priming problems persist. Common culprits include loose pump lid, damaged O-rings, or cracks in the suction plumbing. Even small leaks can prevent proper priming by allowing air to continuously enter the system.

For systems with particularly long suction runs or multiple suction points, you might need to add water directly to the skimmer or use the recirculate setting on multiport valves to help establish initial flow.

Understanding your pool's filtration system can help you identify the best priming approach for your specific setup.

Maintaining Proper Prime

Once your system is running properly, monitor it for the first few hours to ensure prime holds steady. Occasional air bubbles are normal initially, but they should decrease and eventually stop as all air purges from the system.

Keep your pump basket clean and water levels adequate in your skimmer to prevent future priming issues. Low water levels are one of the most common causes of lost prime during normal operation.

Regular maintenance following proper weekly maintenance procedures will minimize situations where repriming becomes necessary, keeping your pool system running efficiently season after season.