Why Is My Pool Pump Leaking Water? Causes and Repair Guide
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A pool pump leaking water is one of the most common repair calls we receive at Perth Pool Pump Rescue. Whether you have noticed a puddle forming underneath your pump, water dripping from the connections, or a steady stream running across the pad, a leak should never be ignored. Left unrepaired, even a small leak can damage the motor, corrode electrical components, and lead to a much more expensive replacement.
In Perth, the combination of heat, UV exposure, and bore water minerals can accelerate seal and fitting wear. Below is a guide to the most common causes of pool pump leaks and what you can do about each one.
1 Shaft Seal Failure
Signs: water dripping from the base of the pump body, directly underneath the motor
The shaft seal sits between the wet end (impeller housing) and the dry end (motor) of your pump. Its job is to prevent water from reaching the motor bearings and windings. Over time, heat cycling, chemical imbalance, and Perth's sandy bore water can wear this seal down, causing water to seep through.
A shaft seal replacement is one of the most common pool pump repairs. The pump needs to be disassembled, the old seal removed, and a new mechanical seal pressed into place. This is a job for a qualified technician because incorrect installation will cause the new seal to fail within weeks.
2 Loose or Cracked Unions and Fittings
Signs: water leaking from the pipe connections on the inlet or outlet side of the pump
Pool pump unions use rubber O-rings to create a watertight seal. Over several summers of UV exposure and chlorine contact, these O-rings dry out, crack, and lose their ability to seal. The union itself can also crack from overtightening or impact.
Turn off the pump and inspect the unions. In many cases, replacing the O-ring and hand-tightening the union is enough. If the union body is cracked, the entire fitting will need to be replaced. Always use a pump-rated O-ring lubricant, never petroleum-based grease.
3 Cracked Pump Housing (Volute)
Signs: water seeping from the pump body itself, often visible as a wet patch or hairline crack
The pump housing, also called the volute, is the plastic or cast-iron casing that holds the impeller. A crack can develop from over-tightening the lid, freezing water inside the pump (rare in Perth but possible on cold nights with standing water), or impact damage during maintenance.
Small hairline cracks can sometimes be sealed with a specialist pool pump epoxy, but this is usually a temporary fix. A cracked volute typically means the pump body needs replacing. Depending on the age of the pump, a full replacement may be more cost-effective than sourcing a new housing.
4 Pump Lid O-Ring Failure
Signs: water leaking from around the clear pump lid or strainer basket area
The pump lid O-ring creates the seal between the strainer basket lid and the pump body. This is one of the easiest components to check because it is right on top. If the O-ring is flat, cracked, or has debris stuck to it, the seal will fail and water will leak out during operation.
Remove the pump lid, clean the O-ring groove, and inspect the O-ring. If it has lost its round shape or has visible cracks, replace it. Apply silicone-based lubricant to the new O-ring before reinstalling the lid. Do not overtighten the lid as this can warp the seal.
5 Damaged Drain Plug
Signs: water dripping from the bottom of the pump near a small threaded plug
Most pool pumps have one or two drain plugs at the base of the pump body. These are used to drain the pump for winterisation or maintenance. If the plug is loose, cross-threaded, or its washer is worn, water will slowly leak from this point.
Check that the drain plug is tight and the Teflon tape or washer is intact. If the plug threads are damaged, replace the plug. This is a straightforward and inexpensive repair, but ignoring it can lead to ongoing water loss and pad erosion.
Important: Never run a leaking pool pump. Water and electricity are a dangerous combination. If your pump is leaking near the motor or electrical connections, turn it off at the circuit breaker and call a technician. Continuing to operate a leaking pump risks electrical shock, motor burnout, and further damage.
When to Call a Professional
Some pool pump leaks have simple fixes that a handy homeowner can handle, such as replacing a lid O-ring or tightening a union. However, shaft seal replacements, cracked housings, and any leak near the motor should always be handled by a qualified pump repair technician.
At Perth Pool Pump Rescue, we offer a collect-and-return service. We pick up your pump, repair it in our workshop, and return it ready to reinstall. This means no call-out fees and a faster turnaround than waiting for an on-site visit.
Frequently Asked Questions
How much does it cost to fix a leaking pool pump in Perth?
The cost depends on the cause of the leak. A simple O-ring replacement may cost under $50 in parts, while a shaft seal replacement typically ranges from $150 to $250 including labour. A cracked pump housing may require a full pump replacement. Contact us for a free diagnosis when you drop off your pump.
Can I use silicone or tape to stop a pool pump leak?
Teflon tape is appropriate for threaded fittings and drain plugs. Silicone sealant can work as a very temporary measure on minor cracks, but it is not a permanent fix. Using the wrong sealant can actually make the problem worse by contaminating the seal surfaces. For a lasting repair, have the damaged component replaced.
Is a leaking pool pump dangerous?
Yes, a leaking pool pump can be dangerous. Water near the motor or electrical connections creates a risk of electrical shock. It can also cause the motor bearings to rust and seize, leading to motor failure. Always turn off a leaking pump at the circuit breaker and arrange a repair.
Why is my pool pump leaking when it is turned off?
If your pump leaks only when turned off, the issue is usually a check valve problem or gravity-fed backflow through a cracked fitting. Water from the pool can siphon back through the system and find the weakest seal. This is different from a pressure-side leak that only appears when the pump is running.
What brands of pool pump do you repair?
We repair all major brands including AstralPool, Zodiac, Davey, Onga (Pentair), Waterco, MADIMACK, Hurlcon, Poolrite, Speck, Baracuda, Neptune, B and L Pumps, and all other brands sold in Australia.
Perth Suburbs We Service
We collect and return pool pumps across Perth North of the River, including:
- Joondalup
- Wanneroo
- Scarborough
- Stirling
- Osborne Park
- Innaloo
- Karrinyup
- Balcatta
- Northbridge
- Leederville
- Mt Lawley
- Inglewood
- Bayswater
- Morley
- Dianella
- Nollamara
- Marmion
- Duncraig
- Warwick
- Greenwood
- Kingsley
- Woodvale
- Hillarys
- Padbury
- Craigie
- Sorrento
- Carine
- Doubleview
- Wembley
- Subiaco
Pool Pump Leaking? We Can Fix It
Perth Pool Pump Rescue provides fast, affordable pool pump leak repairs across Perth North of the River. We collect your pump, repair it in our workshop, and return it ready to install. No call-out fees.
Call 0468 305 950Open Monday to Friday, after 5pm and weekends by appointment
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