Filtration & Circulation /
Why does my pool pump keep losing pressure?
A pool pump that keeps losing pressure usually has a flow restriction, an air leak, or a filter problem. Start with water level, baskets, and the filter.
Archive date: this article was written for PoolSkimmer on Oct 24, 2026 and given the earlier archive date of Sep 23, 2025 so the blog reads as an organized archive. It was not published on that date.
Why is the pool pump losing pressure?
In most cases, a drop in pressure is down to restricted water flow or air making its way into the system. You will find that the usual suspects are a low water level in the pool, a clogged skimmer or basket, a filter in need of attention, a valve not quite open, or an air leak on the suction side. It is best to begin with the simple checks, but make sure the pump is off before you put your hands on any lid or basket.
Where to start
To avoid overlooking the obvious, work through these in order:
1. The water level. Should it be too low, the skimmer will draw in air rather than a steady stream of water and the pump may lose its prime or run with weak pressure. 2. The skimmer basket. Any debris here will impede the water before it even gets to the pump. 3. The pump strainer basket. Only open the lid once the equipment is safe to handle and the pump has been shut down. 4. The filter. If it is dirty, expect a loss of pressure and reduced flow. Consult the manufacturer for the proper way to clean or backwash.
Is it debris?
Quite often it is. Fine material, insects and leaves can build up in the filter and baskets. This kind of restriction tends to manifest as a falling gauge reading or a pump that runs fine at first then weakens over time. You may notice the return jets are not as strong, the pump has an odd sound, or the gauge will not hold its normal number. Even after you have cleaned the basket, the system might improve for a while only to let you down again.
What if everything is clean?
When the pump continues to underperform, you should look for plumbing issues or air leaks.
- Suction side air leak: An imperfect seal, a loose lid or a worn O-ring will allow air to enter and disrupt the flow.
- Valve or blockage: A valve left partially closed or something in the line will hamper circulation.
- Pump condition: Worn internals, a damaged impeller or debris in the housing can all take their toll on performance.
- Electrical or heat: If the motor is running hot, shutting down or there are electrical faults, leave the system alone and get someone to look at it.
When to bring in a pro
A qualified pool professional should be called if cleaning has done nothing to restore pressure, or if the pump will not stay full of water and keeps losing its prime. The same applies if you see air in the return jets or the lid, or if you have reason to believe there is a problem with the impeller, a valve or the seals. Unusual noises and overheating are also cause for concern.
Things to steer clear of
Never put your hand into operating suction equipment or try to unblock the suction side with the pump running. Leave any electrical work to those qualified to do it. Be sure to wear the right PPE and heed the instructions on your equipment manual and chemical labels.
If routine cleaning does not stop the pressure from dropping, do not just keep the system running in hopes it will sort itself out. The next logical step is to put in some time to diagnose a possible air leak, blockage or a part of the pump that has seen better days.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)