As an Amazon Associate I earn from qualifying purchases. The "Search Amazon" buttons and the "Worth a look" links on this page are Amazon affiliate links; we show no prices or ratings. Facts recorded Oct 25, 2026 from the official sources linked on each section. Manufacturer pages and rules change, so check the current version and your model's manual.
Difficulty: easy checks; seal, motor and wiring work is for a pro
Safety first
- Power off first. Pentair says to turn off the breaker for the pool pump before maintenance and to confirm the system isn't running before you open a pump. Keep the breaker off while you work (lock or tag it if you can so nobody switches it back on). Pentair: 7 Servicing Tips
- GFCI. Pentair's IntelliFlo3 guide says to connect the pump only to a GFCI-protected branch circuit and to contact a qualified electrician if you can't verify that the circuit is GFCI-protected. Pentair IntelliFlo3 VSF guide
- Wiring, bonding and grounding are electrician work. We don't give instructions for them.
- Relieve pressure first. Pentair says to disconnect power at the breaker and relieve pressure in the filtration system before servicing the pump: open the filter's air relief valve and stand clear of the filter until the gauge reads 0 psi. Pentair IntelliFlo3 VSF guide
- Never run the pump dry. Pentair says running dry damages the shaft seal and the pump will start leaking; Hayward says water acts as a coolant and lubricant for the mechanical shaft seal. Pentair: don't let the pump run longer than 30 minutes without priming. Pentair guide; Hayward Super Pump manual
The question
"Is it a cheap O-ring, seal or basket problem, or a dead motor? What can I check safely?"
Check these first (owner-level)
- Pool water level. Pentair says to keep it about halfway up the skimmer opening. If it falls below the opening, the pump draws air through the skimmer, loses prime and can run dry.
- Strainer pot full of water. Both makers list an empty strainer housing as a cause. Pentair: fill the strainer pot up to the suction port.
- Lid O-ring. Pentair: check and clean the strainer pot lid O-ring and make sure it's seated, not pinched. Hayward: keep the cover O-ring clean, seated in its groove and lubricated (Hayward names "Jack's 327"), with the cover locked firmly.
- Baskets. Hayward lists a strainer or skimmer basket "loaded with debris" as a cause. Pentair says full skimmer baskets add friction and energy use.
- Suction-side air leaks. Hayward: "Any self-priming pump will not prime if there are suction air leaks," and leaks can show as bubbles coming from the return fittings on the pool wall. Check for loose suction-side unions and leaking valve O-rings. Pentair adds that cracked, stretched or aged O-rings are a common, often cheap, cause.
- Valves. Pentair's priming steps have all suction and return valves open before power is restored.
- Variable-speed priming settings. On the IntelliFlo3, Pentair lists "priming speed or range too low" as a cause and says to adjust the priming parameters until the pump primes consistently.
Source: Pentair IntelliFlo3 VSF guide (priming, troubleshooting); Hayward Super Pump manual (troubleshooting); Pentair: 7 Servicing Tips
Pentair's priming steps (IntelliFlo3 VSF)
- Stop the pump and disconnect all power at the breaker.
- Close all valves in the suction and return lines.
- Open the filter's air relief valve and stand clear until pressure reads 0 psi.
- Remove the strainer pot lid and fill the pot up to the suction port with water.
- Put the lid back, O-ring seated and not pinched, and tighten until the lid handles are perpendicular to the suction port.
- Open all suction and return valves; open the filter's air relief valve and stand clear of the filter.
- Restore power at the breaker. The pump begins its priming cycle if enabled.
Source: Pentair IntelliFlo3 VSF guide, Priming the Pump
Other pumps have their own steps; use your model's manual.
Signs it's more than an O-ring
- Leak from the middle of the pump: Pentair says that can mean the mechanical seal between the impeller and motor is worn. Hayward says only qualified personnel should attempt shaft seal replacement.
- Unusual noise: Pentair says it may indicate debris stuck in the impeller.
- Motor hums but doesn't start: Hayward lists an impeller jammed with debris and says to have a qualified repair professional open the pump.
- Suction side clogged: Hayward says to contact a qualified repair professional (and that only your pool dealer can confirm suction with a vacuum gauge).
- Pump runs then stops: Pentair's chart lists over-temperature and over-current faults. Hayward says low voltage (often from undersized wiring or extension cords) can shut a motor off, and to have a qualified professional check the wiring.
Source: Pentair: 7 Servicing Tips; Hayward Super Pump manual; Pentair IntelliFlo3 VSF guide
Repair or replace?
We don't have a manufacturer rule for when to replace a whole pump, so we don't give one. If the cheap checks above don't fix it, have a pro diagnose the seal, impeller or motor before you buy. If you do replace it, read the variable-speed pump rules and how to size a replacement pump first.
Should you DIY? / When to call a pro
Fine to DIY: water level, emptying baskets, filling the strainer pot, cleaning and lubricating the lid O-ring, looking for bubbles at the returns, checking valve positions, and priming settings in the pump's app or controls.
Call a qualified pool professional: shaft seals, opening the pump to clear the impeller, clogged suction lines, suction outlets. Call a licensed electrician: wiring, voltage problems, GFCI trips.
See our full When to Call a Pro page. Follow your model's manual; this site isn't a substitute for it, and it isn't legal advice.
If your model isn't listed
The numbers on this page come from specific manufacturer documents and models. If your equipment isn't one of them, don't assume the same numbers apply: find the model number on the rating plate, open that model's manual on the manufacturer's site, or contact the manufacturer. You can also email us with the brand and model number.
Facts from the manufacturer (and where else they came from)
Where to look
Pump links are in the “Worth a look” box above. These buttons cover small parts and supplies the makers mention; match the O-ring to your pump model. As an Amazon Associate I earn from qualifying purchases.
- Pump lid O-ring: match your pump's brand and modelSearch Amazon
- O-ring lubricant: Hayward names Jack's 327 for its cover O-ringSearch Amazon