Pool equipment problems rarely happen all at once — they develop gradually and announce themselves with early warning signs before they become failures. Knowing what those signs mean, and how urgent each one is, helps you respond appropriately: some issues need immediate attention, others can wait for the next scheduled service visit. This guide covers the most common equipment problems pool owners encounter.
Pump problems
Loss of prime / pump won't pull suction
Symptoms: The pump runs but water flow drops to near zero. The pump basket may be empty of water or filling with air bubbles. Return jets may stop flowing or flow with air.
Common causes: Air leak in the suction line (cracked pipe, failed O-ring on the pump lid, loose fittings), water level too low (skimmer sucking air), clogged skimmer or pump basket, or closed/partially closed suction valve.
First checks: Confirm water level is at mid-skimmer. Empty and check skimmer and pump baskets. Inspect the pump lid O-ring and reseat the lid firmly. Check that all valves are fully open.
Urgency: High — a pump running dry damages the impeller and seal within minutes. Shut the pump off if it's not priming after 60–90 seconds of running.
Unusual pump noise
Grinding or shrieking: Bearing failure. The motor bearings are wearing — this will progress to complete motor failure. Schedule a repair or motor replacement.
Rattling or clanking: Debris in the impeller, or a loose component in the pump housing. Debris in the impeller should be cleared — shut the pump off, remove the basket, and check whether anything has passed through to the impeller.
Cavitation (gurgling/bubbling sound): The pump is drawing air — see loss of prime causes above. Also caused by a pump that's oversized for the system's plumbing, causing it to pull suction faster than the pipes can supply.
Urgency: Grinding/shrieking = schedule repair promptly. Rattling = investigate and clear debris. Cavitation = identify and resolve air source.
Tripping the breaker
Symptoms: The pump trips its circuit breaker when running, or won't start without tripping it.
Common causes: Failing capacitor (common in single-speed motors), motor winding failure, moisture in the motor, or a short in the wiring.
Urgency: High — do not repeatedly reset the breaker without diagnosing the cause. Electrical faults can be dangerous and will worsen with each trip. Call a pool professional or electrician.
Filter problems
Pressure consistently high, won't normalize after backwash
Sand filters: Sand has reached the end of its service life and has channeled (water is flowing around the sand rather than through it). Sand replacement is needed. Alternatively, a broken lateral (the collection tubes at the bottom of the tank) is allowing sand to bypass the filter — you'll see sand in the pool or returns.
Cartridge filters: Cartridge is due for replacement — soaking and rinsing no longer restore adequate flow. Inspect the pleats for damage and replace if they're collapsed, torn, or excessively fouled.
DE filters: Grids have a buildup of oils and mineral deposits that backwashing isn't removing. Full breakdown cleaning needed.
Sand or DE material appearing in the pool
Sand in pool: A broken lateral inside the sand filter is allowing sand to pass through. Filter needs to be opened and laterals inspected/replaced.
DE in pool: A torn or cracked DE grid is allowing DE to pass through. Filter needs breakdown inspection and grid replacement.
Urgency: Moderate — the pool is swimmable but the filter isn't functioning correctly. Schedule service.
Water loss / leaks
Pool losing water faster than evaporation explains
First check — the bucket test: Fill a bucket to pool water level, set it on a pool step, and mark both the pool water level and the bucket water level. After 24 hours without swimming, compare: if the pool dropped more than the bucket, the difference is actual water loss beyond evaporation. If they dropped equally, what you're seeing is evaporation, not a leak.
Common leak sources: Skimmer body cracks (common in Florida due to ground movement), light fixture gaskets, return fittings, main drain, underground plumbing (less common but more serious), and equipment pad connections.
Urgency: Significant ongoing water loss (more than 1/4 inch per day beyond evaporation) warrants professional leak detection. Small losses may be manageable but should be monitored and investigated.
Heater problems
Heater won't ignite (gas)
Common causes: Dirty or failed pilot assembly, clogged burner orifices, failed igniter, low gas pressure, or a safety lockout from a previous fault.
First checks: Confirm gas supply is on. Check for error codes on the heater's display panel — modern heaters are diagnostic and will display a fault code. Reset the heater per manufacturer instructions if it's in fault lockout.
Urgency: Gas heater issues that don't resolve with a simple reset should be diagnosed by a licensed technician — don't attempt gas system repairs without proper qualifications.
Heat pump not reaching temperature
Common causes: Dirty evaporator coil (the outdoor section), refrigerant issue, failing compressor, or ambient temperature below the heat pump's operational minimum (most heat pumps don't work well below 50°F).
First check: Clean debris from around and within the evaporator coil — restricted airflow is the most common cause of heat pump efficiency loss.
Salt chlorinator problems
Salt cell producing low chlorine output
Common causes: Salt level out of range, calcium scale buildup on cell plates, cell reaching end of service life (typically 3–5 years), or flow sensor fault.
First check: Test salt level (target range varies by system — typically 2,700–3,400 ppm). Inspect cell plates for visible white scale buildup. Clean the cell with a dilute acid solution if scale is present.
"Check salt" or "low salt" warning despite adequate salt level
Common causes: Scale on the salt sensor giving a false reading, or a failing cell that can no longer read salt accurately. Clean the sensor and cell — if the warning persists with confirmed adequate salt level, the cell may need replacement.