Pool Skimmer Not Working

What a Pool Skimmer Actually Does

The skimmer sits at the waterline and draws surface water, along with leaves, insects, sunscreen residue and other debris, into your filtration system before it sinks to the bottom. When it stops working properly, debris accumulates on the surface, your water clarity suffers, and your pump can end up working harder than it should.

Most skimmer problems come down to a handful of causes. The good news is that several of them are straightforward to check yourself.

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What Usually Causes a Skimmer to Stop Working

Low Water Level

This is the most common cause and the first thing to check. If the water level drops below the midpoint of the skimmer opening, the skimmer will start drawing air instead of water. This breaks the surface suction and can cause the pump to lose prime.

The water level should sit roughly halfway up the skimmer opening. If it's lower than that, top up the pool and see whether the skimmer resumes normal operation.

A Blocked Skimmer Basket

The skimmer basket catches debris before it reaches the pump. If the basket is full or clogged, water flow through the skimmer is restricted. This is easy to miss if you're not checking it regularly.

Remove the skimmer lid, lift out the basket, and clear any debris. Rinse it with a hose if needed before replacing it.

A Stuck or Missing Weir Flap

The weir is the small hinged flap at the front of the skimmer opening. It allows water and debris to flow in while preventing what's already been captured from floating back out. If the weir is stuck open, stuck closed, or missing entirely, the skimmer won't function as intended.

Check that the weir moves freely. If it's warped, broken or absent, it can be replaced, this is a low-cost fix.

Blocked or Cracked Skimmer Line

The pipe running from the skimmer to the pump can become partially blocked with debris, or it may have developed a crack. A crack in the line can draw air into the system, reducing suction at the skimmer and potentially causing the pump to lose prime.

Signs of a line issue include persistent air bubbles in the pump basket, reduced flow at the skimmer, or a pump that struggles to hold prime even after the basket is cleared.

Suction Split Between Fittings

Many pools have both a skimmer and a main drain, with the pump drawing from both. If the valve controlling the balance between these two inlets is set incorrectly, or if a fitting elsewhere is drawing more suction than intended, the skimmer may receive too little flow to work properly.

Check the valve settings on your equipment. The skimmer line should generally be receiving the majority of the suction during normal operation.

Air Leak in the System

An air leak anywhere between the skimmer and the pump, at a union, a lid seal, or a fitting, can reduce suction at the skimmer. If you're seeing air bubbles in the pump basket or the water returning through the jets looks frothy, an air leak is worth investigating.

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What You Can Safely Check Yourself

Before calling a technician, work through this list in order:

• Check the water level. It should sit at the midpoint of the skimmer opening.
• Clear the skimmer basket. Remove it, empty it, and rinse it clean.
• Inspect the weir flap. Make sure it moves freely and isn't broken or missing.
• Check the pump basket. A blocked pump basket reduces flow throughout the system, including at the skimmer.
• Look at the valve settings. Confirm the skimmer line is open and receiving adequate suction.
• Look for visible cracks. Inspect the skimmer body itself for any obvious cracking around the opening or the throat.

If the skimmer resumes normal operation after working through these steps, you've likely resolved the issue. Keep an eye on it over the next few days to confirm.

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What Needs a Technician

Some skimmer problems go beyond what a pool owner can reasonably fix without specialist tools or knowledge.

Call a pool technician if:

• The pump is losing prime repeatedly and you can't identify the cause
• You suspect a cracked or blocked underground skimmer line
• There are visible cracks in the skimmer body itself that extend below the waterline
• The skimmer throat or housing is damaged and needs replacing
• You're seeing persistent air bubbles in the system and can't locate the source of the air leak

Underground pipe issues in particular require pressure testing and, in some cases, excavation. These aren't DIY jobs.

Sparkling Pools carries out equipment diagnosis and repair across Auckland. If you've worked through the checks above and the skimmer still isn't performing, it's worth having a technician take a look before the problem puts unnecessary strain on your pump.

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Keeping Your Skimmer Working Well

A few simple habits go a long way:

• Check and empty the skimmer basket at least once a week, more often during autumn when leaf fall is heavy
• Keep the water level consistent. Top up the pool after periods of heavy use or evaporation during summer
• Inspect the weir flap periodically. UV exposure and age can cause it to warp or become brittle over time
• Schedule regular servicing. A technician checking your equipment annually can catch developing issues, worn seals, early-stage cracks, valve wear, before they become bigger problems

Auckland's outdoor pools deal with a fair amount of debris year-round, particularly in areas with established trees nearby. Staying on top of the skimmer basket is one of the simplest things you can do to keep your filtration system running efficiently.