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Skimmer Symptom Checker

Check what your skimmer is doing and work through the most likely fixes in order.

Pick your symptoms

Check everything that matches what you see.
Most likely fixes (do in order):
Safety: Turn off power before opening pump lids or working around equipment. If you suspect an underground suction leak, contact a qualified pool professional.

Understand What Your Skimmer Is Telling You

The Pool Skimmer Companion Guide goes beyond the symptom checker with skimmer anatomy, water level, weir operation, suction, diverters, skimmer/main-drain relationships and practical troubleshooting.

$7 Digital Companion Guide
Get the Pool Skimmer Companion Guide

Understanding Common Skimmer Problems

A pool skimmer depends on the correct water level, open suction lines, clean baskets, a working weir door and a sealed pump system. When one piece is wrong, surface debris may stop moving toward the skimmer or air may enter the circulation system.

Weak Skimmer Pull

Weak pull is often caused by a clogged basket, dirty filter, closed or poorly balanced valves, low pump speed or debris near the pump impeller. Start with the simple checks before assuming the underground line is blocked.

Air Bubbles and Loss of Prime

Air entering the suction side can reduce skimmer performance and cause bubbles at the returns. Common sources include low water, a damaged pump-lid O-ring, loose drain plugs, leaking unions or a suction-line leak.

Weir Door Problems

Multiple Skimmers With Uneven Flow

When one skimmer is strong and another is weak, valves may be unbalanced or one line may be partially clogged. A completely inactive line may need additional troubleshooting or professional testing.

Dead Spots and Poor Surface Movement

Return direction affects skimming. A gentle circulation pattern can help move floating debris toward the skimmer instead of allowing it to collect in corners.

Frequently Asked Questions

Why does my skimmer barely pull?

Start with water level, baskets, filter condition, pump operation and valve position. Those common issues are easier to rule out before investigating a clogged or leaking suction line.

Why do I see bubbles coming from my returns?

Bubbles can indicate air entering the suction side. Low water and pump-lid sealing problems are common places to start looking.

Does a missing weir door matter?

Yes. The weir helps concentrate surface flow into the skimmer and helps keep collected debris from floating back into the pool when the pump stops.

Should I close the main drain to get stronger skimmer suction?

Some systems allow suction to be balanced between the skimmer and main drain, but identify the plumbing and understand the valve arrangement before making changes.

Pool Gal Pro Tip 💦
Start simple: water level, weir, baskets, filter and valves. Those five checks solve a surprising number of “my skimmer isn’t working” problems before you ever need to start blaming underground plumbing.

Watch: Skimmer Troubleshooting

Pool Skimmer Companion Guide

Your skimmer does more than catch leaves — understand how it really works.

  • How a pool skimmer actually works
  • Basket, weir door and suction explained
  • Common causes of weak skimmer suction
  • What to check when it isn't pulling properly
  • Cleaning, maintenance and mistakes to avoid
Get the Companion Guide – $7
Instant download • Use on any device • Print as needed

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