Symptoms
- Pump runs but no water flows through the system
- Pump loses prime shortly after starting
- Air bubbles visible in the pump strainer basket
Likely causes
- CommonLow water level in the pool below the skimmerThe pump can't draw water if the skimmer intake is above the waterline.
- CommonClogged skimmer or pump basketDebris blocking the basket restricts water flow needed to prime.
- CommonAir leak at a suction-side fitting, o-ring, or lid gasketAny small air leak on the intake side prevents the pump from building suction.
- PossibleWorn pump lid o-ringA cracked or dried-out lid seal is one of the most common leak points.
What to do
- Check the pool water level and add water if it's below the skimmer opening.
- Turn off the pump and clean out the skimmer basket and pump strainer basket of leaves and debris.
- Inspect the pump lid o-ring for cracks or dryness and apply pool-safe lubricant, or replace if worn.
- Check all visible suction-side unions and fittings for air leaks, tightening or resealing as needed.
- Fill the pump strainer housing with water manually before restarting to help it prime faster.
- Turn the pump on and watch the strainer basket; steady water flow without air bubbles confirms a good prime.
Tools and parts
- Pool-safe silicone lubricant
- Garden hose (to refill pump housing)
Pool pump lid o-ringSearch: “pool pump lid o-ring seal”
Pump union o-ringsSearch: “pool pump union o-ring gasket”
When to call a pro
If the pump still won't prime after checking seals and baskets, a pool technician can check for a cracked impeller housing or deeper suction line leak.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.