Pool Skimmer Not Working: Causes and Fixes
The most common reason a pool skimmer stops working is low water level. When pool water drops below the skimmer opening, the pump pulls air instead of water and suction breaks immediately. Check the water level first. The second most common cause is a clogged or misseated skimmer basket. Fix these two and you resolve 80% of skimmer problems in under 5 minutes.
Is this guide for you?
This guide is for you if:
- Your skimmer is pulling no water from the surface
- Suction at the skimmer has dropped noticeably
- The pump is running but surface debris is not clearing
This guide is NOT for you if:
- You want routine skimmer basket care: see our pool skimmer basket maintenance guide
- Your pool vacuum connected to the skimmer is the problem: see pool vacuum suction problems
Video guide
Video: “The Easiest Way to UNCLOG your Swimming Pool Skimmer!” by Hallmark Pool Supplies
Causes checklist: start here
We recommend running through this table before jumping to any individual fix. It narrows down the likely cause in under 2 minutes.
| # | Cause | Check | Fix |
|---|---|---|---|
| 1 | Water level too low | Is waterline below skimmer opening? | Top up pool with garden hose |
| 2 | Skimmer basket clogged or misseated | Empty basket; is it sitting flat? | Empty and reseat basket |
| 3 | Weir door stuck closed | Does flap swing freely? | Clear debris; free the flap |
| 4 | Pump or air leak issue | Air bubbles at return jets? | Diagnose suction side |
| 5 | Skimmer line blocked | No improvement after all above | Professional flush ($150-$300) |
Per InYoPools skimmer troubleshooting guidance, water level and basket issues{:target=“_blank”} account for the large majority of residential skimmer problems.
Fix 1: check water level
Optimal pool water level for skimming is mid-way up the skimmer opening, roughly halfway up the rectangular skimmer mouth. At this level, the pump draws surface water continuously.
Too low: the skimmer mouth is partially exposed to air. The pump pulls air instead of water, suction breaks, and the skimmer stops flowing. Surface debris accumulates immediately.
Too high: the skimmer opening is submerged. Floating debris cannot enter efficiently because there is no surface flow into the skimmer mouth. Skimming performance drops even though the pump is running.
Fix: top up the pool with a garden hose until water reaches mid-skimmer level.
Why water level drops faster than expected:
- Evaporation in summer heat (up to 1 inch per day in hot, dry climates)
- Splash-out from heavy bather use
- Water loss during backwashing (a standard backwash cycle can waste 200-300 gallons)
If your pool loses more than 1 inch per day without heavy use, that may indicate a leak rather than normal evaporation. See our pool pump troubleshooting guide for leak detection steps.
Fix 2: inspect and reseat the skimmer basket
A misseated or cracked skimmer basket allows air to bypass into the suction line, breaking the pump’s prime and reducing skimmer flow immediately. This is the second most common cause of skimmer problems.
- Remove the basket from the skimmer housing
- Empty it completely (even partial debris load reduces flow)
- Inspect the basket for cracks, even hairline fractures allow air infiltration
- Reinsert the basket carefully: it must sit perfectly flat in the housing, not tilted or angled
- If you use a skimmer plate or vacuum plate over the basket: verify it is fully seated flat
A cracked or misseated skimmer basket allows air to bypass into the suction line, breaking the pump’s prime and reducing skimmer flow. Always check basket seating and condition before more complex troubleshooting.
For basket replacement intervals and cleaning procedure, see our pool skimmer basket maintenance guide.
Fix 3: check the weir door
The weir door is the plastic flap at the front of the skimmer opening. It swings inward to allow surface water and debris to enter, then closes when the pump is off to prevent debris from floating back into the pool. Many pool owners do not know it exists, but it is worth inspecting.
- Stuck closed: debris or grime has wedged the flap shut. Push it with your hand, it should swing freely in both directions.
- Stuck open: the flap stays open even when the pump is off. This does not affect active skimming but means debris escapes back into the pool between pump cycles.
- Missing entirely: common on older pools. A replacement weir door costs $5-$15 at any pool supply store. Not critical for function, but improves skimming efficiency.
If the weir door is stuck: remove visible debris, then lubricate the hinge with a small amount of silicone lubricant or petroleum jelly. Do not force it, the hinge is plastic and breaks easily.
Fix 4: check for pump and air leak issues
If the water level is correct and the basket is fine, look at the pump side of the system.
Diagnostic signal: air bubbles returning through the return jets while the pump is running. If you see bubbles at the jets, air is entering the suction side somewhere between the skimmer and the pump.
Common suction-side air entry points:
- Pump lid O-ring: most common source. The lid must seal completely. Inspect the O-ring for cracking or deformation; lubricate with pool-safe O-ring lubricant (not petroleum-based).
- Cracked pump basket or basket housing
- Loose union fittings on the suction line
- Cracked vacuum hose if one is connected
For full pump diagnostics, see our pool pump troubleshooting guide and the Hayward pool skimmer FAQ{:target=“_blank”} for brand-specific guidance.
Also confirm your filter pressure is not restricting flow. A dirty filter running 8-10 PSI above its clean baseline reduces suction everywhere in the system, including at the skimmer. See pool filter and pump maintenance for service steps.
Fix 5: possible skimmer line blockage
If all four fixes above check out and the skimmer still has no flow, the suction line between the skimmer and the pump may be blocked.
Other causes of suction line blockage:
- Debris that passed through the basket and lodged in the line
- Root intrusion in older plumbing
- A scale buildup or biofilm restriction over time
DIY test: disconnect the suction line at the pump; use a garden hose to back-flush the line toward the skimmer. If water flows through freely, the line is clear.
Professional fix: pressure flushing, hydro-jetting, or camera inspection for root intrusion. Cost runs $150-$300 for professional line clearing. See pool service professional standards{:target=“_blank”} from NSPF to find certified technicians.
When the skimmer body is damaged
If none of the above resolves the problem and you notice wet or soft soil near the skimmer deck, or the pool waterline drops specifically near the skimmer, the skimmer body itself may be cracked.
Signs of a cracked skimmer housing:
- Water seeps into the surrounding soil, eventually destabilizing the concrete or deck around the skimmer
- Visible cracks in the skimmer body walls
- Waterline loss localized to the skimmer side of the pool
Repair options:
- Minor cracks: epoxy repair kit ($20-$50 DIY)
- Severe damage: skimmer body replacement ($200-$600 professional, including labor)
This is beyond DIY scope for most pool owners. Call a pool service company.
FAQ
Why is my pool skimmer not pulling water?
The most likely cause is low water level or a clogged, misseated skimmer basket. Check water level first: the waterline should be mid-way up the skimmer opening. Then inspect the basket seating. These two causes account for the majority of residential skimmer problems.
What is the correct pool water level for skimming?
The pool water should sit mid-way up the skimmer opening, roughly halfway up the rectangular mouth. Too low and the pump pulls air; too high and the skimmer mouth is submerged and cannot collect floating debris efficiently.
My skimmer basket is empty but the skimmer still is not working. why?
Check the weir door (it may be stuck closed), look for air bubbles returning from the jets (air leak in the suction side), and verify the pump is generating full pressure. A stuck weir door or suction-side air leak can reduce or stop skimmer flow even with a perfectly clean basket.
Can a skimmer work with a cracked basket?
Technically yes, but a cracked basket allows air into the suction line and reduces suction. We recommend replacing a cracked basket immediately. Replacement baskets cost $10-$30 at most pool supply stores.
When should I call a professional about my skimmer?
If basic troubleshooting (water level, basket, weir door, air leaks) does not restore skimmer flow, the suction line may be blocked or the skimmer body may be cracked. Both require professional diagnosis. Budget $75-$150 for a service call and $150-$300 for line clearing if needed.
For a full overview of regular pool maintenance tasks that prevent equipment problems, see our pool maintenance guide for beginners.