7 Signs Your Pool Pump Is Failing (And When to Replace It)

Here is the comprehensive guide, enriched with local Phoenix insights and updated 2026 data.

Your pool pump is the heart of your pool’s circulation system, and here in the Valley of the Sun, that heart works a lot harder than in other parts of the country. When it starts to fail, you’ll notice problems quickly—especially during our intense summer heat.

1. Strange Noises

Grinding or Screeching (The “Screaming Metal” Sound)

If your pump sounds like rocks in a blender, the motor bearings are likely failing. In our experience, this is often caused by the rear bearing (typically a standard 6203 or 6204 part) seizing up due to heat or age.

Insider Tip: Not sure if it’s the motor? Place the tip of a long screwdriver against the motor body and put your ear to the handle. You will hear the grinding clearly through this makeshift stethoscope if the bearings are the culprit.

Loud Humming

The motor is trying to start but can’t. This is almost always a bad capacitor or damaged motor windings.

Repair possible? Start capacitors are affordable (usually $20-$40 for the part). However, if the motor windings are blackened or smell burnt, you are looking at a full motor replacement.

Cavitation (Sucking Sound)

This sounds like gargling rocks. The pump isn’t getting enough water. While this can be a simple clog, it often indicates the impeller is damaged or stripped.

Repair possible? If the brass insert on the impeller has spun loose from the plastic, replacement is the only option.

2. Weak Water Flow

Reduced Return Flow

Water returning to the pool through jets should create a visible ripple. Weak flow indicates the pump is struggling to push water against the resistance of the filter and plumbing.

Common Phoenix Causes

Palo Verde Blooms: These tiny yellow flowers are notorious for slipping past skimmer baskets and clogging the pump impeller.
Clogged Impeller: Debris stuck in the eye of the impeller.
Air Leak: A “suction side” leak pulling air into the system.
Motor Losing Power: The motor runs but lacks the torque to spin the impeller at full speed.

When to Worry

Weak flow after you have backwashed or cleaned the filter suggests the pump itself is failing. We recommend checking the pressure gauge: low flow and low pressure usually means a clogged impeller or suction leak.

3. Pump Won’t Prime

What Priming Is

The pump needs to fill with water before it can circulate. This usually happens automatically within 2-3 minutes of startup.

Signs of Priming Problems

Air bubbles that never clear from the pump basket lid.
The pump housing gets hot to the touch because water isn’t cooling it.
You have to manually fill the pot with a bucket every morning.

The “Garden Hose” Trick

If your pump won’t catch, try forcing water into the pump intake with a garden hose wrapped in a rag to create a seal. If it primes instantly but fails again the next day, you likely have a shrunken suction-side plumbing joint—a common issue with Arizona’s extreme temperature swings.

4. Tripping the Circuit Breaker

What’s Happening

The pump draws too much amperage, causing the breaker to trip as a safety measure. In Phoenix summers, ambient temperatures of 110°F+ already put electrical components near their thermal limit.

Possible Causes

Shorting Windings: The insulation inside the motor has melted.
Bad Capacitor: A bulging capacitor top is a dead giveaway.
Locked Rotor: The bearings have seized completely, and the motor can’t turn.

Why It’s Serious

Repeated tripping is a fire hazard. We advise homeowners never to force the breaker back on more than once; if it trips again immediately, the motor is electrically dead.

5. Visible Leaks

Around the Pump Housing

Water dripping from the middle of the pump (between the motor and the wet end) suggests a failed shaft seal.

The Fix: We typically use a PS-200 or PS-201 seal assembly for most residential pumps. It’s a routine repair, but if ignored, that leaking water will travel along the shaft and rust out your motor bearings within weeks.

Housing Cracks

Look for white, crusty calcium buildup on the black plastic housing. This residue often hides hairline cracks caused by UV degradation.

Seal Replacement

Shaft seal replacement is affordable ($150-$250) and extends pump life significantly.

6. Increased Energy Bills

The Numbers

Pool pumps are typically the second-largest energy user in a Phoenix home, right after air conditioning. If your bill spikes, an aging single-speed pump is often the culprit.

Why Pumps Lose Efficiency

Motor windings degrade, increasing resistance and amp draw.
Worn wear rings allow water to recirculate inside the pump rather than going to the pool.
The pump runs longer to do the same amount of work.

The 2026 Reality

Department of Energy (DOE) regulations that fully took effect in 2021 have changed the landscape. Most new pumps over 1.0 Total Horsepower (THP) must be Variable Speed (VS). While the upfront cost is higher, the savings are real.

Quantified Savings: A modern Variable Speed pump running at low RPMs can save $400-$800 annually compared to an old single-speed energy hog.

7. Advanced Age

Expected Lifespan

In our intense climate, equipment ages faster.

Single-speed motors: 6-10 years.
Variable-speed drives: 8-12 years (with proper surge protection).
Pump “Wet Ends”: 10-15 years before plastic becomes brittle.

Even if it runs, a 12-year-old pump is a ticking clock. We often see the composite plastic housing crack simply from the vibration of startup once it becomes brittle from UV exposure.

Repair vs. Replace Decision

The “50% Rule”

We generally recommend replacement if the repair cost exceeds 50% of the price of a new pump—but there is a catch. Because of the DOE regulations mentioned earlier, you may not legally be able to buy a direct single-speed replacement motor if your pump is over 1.0 HP.

Consider Repair When

The pump is under 5 years old.
The housing (wet end) is in perfect condition with no sun rot.
It is a simple issue like a capacitor ($150) or seal ($200).

Consider Replacement When

The motor is 8+ years old.
You want to silent the equipment (VS pumps are whisper quiet).
You are ready to automate your pool with smartphone controls.

2026 Cost Comparison (Phoenix Metro Area)

Repair / Service	Typical Cost
Shaft Seal Replacement	$180 - $280
Motor Capacitor	$140 - $220
Impeller Replacement	$250 - $450
Motor Only (Single Speed)	$500 - $850

New Installation	Typical Cost
Variable-Speed Pump (Installed)	$1,600 - $2,600
Single-Speed Pump (Sub-1HP only)	$900 - $1,400

Note: While SRP and APS previously offered rebates for variable speed pumps, these programs have largely been discontinued or exhausted as of 2025/2026. Do not count on a rebate to offset your cost.

Emergency vs. Planned Replacement

The “Summer Tax”

If your pump dies in July, you are in a difficult spot.

Lead times for specific models can stretch to weeks.
Emergency service calls carry a premium.
Your pool turns green in 48 hours, forcing a costly drain-and-clean.

Planned Replacement Benefits

You can shop for the specific model you want (like the Pentair IntelliFlo or Hayward TriStar).
Installations can be scheduled during cooler months.
You avoid the stress of a green pool.

Our Approach

We diagnose before we recommend. Many “dead” pumps in Phoenix just need a $20 capacitor or a good cleaning of the impeller.

But when it is time to upgrade, our pool equipment services help you navigate the new DOE regulations to find a pump that pays for itself in energy savings.

Call (602) 619-1234 for honest pump diagnostics.