Why Your Pool Heater Isn't Working — And How to Fix It Fast

There's nothing worse than planning a relaxing evening swim in your heated pool, only to discover freezing cold water. As Central Florida's most trusted pool heater repair experts with over 688 five-star reviews, we diagnose and repair pool heaters daily throughout Orlando, Davenport, and surrounding areas. This comprehensive guide will help you troubleshoot common heater problems and know when to call professionals.

Pool Heater Diagnostic Checklist (Start Here)

Before calling for service, run through this systematic checklist to identify the problem:

Common Pool Heater Problems & Solutions

Problem #1: Heater Won't Turn On At All

Possible Causes:

• No power: Tripped breaker, blown fuse, or loose wiring
• No gas supply: Gas valve closed or gas line issue (gas heaters)
• Failed control board: Electronic control system malfunction
• Faulty pressure switch: Heater won't start without proper water flow
• Thermostat failure: Temperature sensor not communicating

DIY Troubleshooting:

• Check circuit breaker panel—reset any tripped breakers
• Verify heater power switch is ON
• For gas heaters: Confirm gas valve is fully open (handle parallel to pipe)
• Ensure pool pump is running (heaters require water flow to operate)
• Check filter pressure—clean filter if pressure is high

When to Call Professional: If breakers repeatedly trip, gas flow issues, or no obvious power problems. Our heater repair specialists offer same-day diagnosis.

Problem #2: Heater Turns On But Doesn't Heat Water

Possible Causes:

• Dirty or clogged heat exchanger: Calcium buildup blocks heat transfer
• Failed heating element: Electric heat pumps with burned-out elements
• Low gas pressure: Insufficient fuel for proper heating
• Faulty gas valve: Gas valve opens but doesn't supply enough fuel
• Restricted water flow: Debris blocking heater internal passages

DIY Troubleshooting:

• Verify pump is running at full speed (not on low-speed setting)
• Clean pool filter thoroughly
• Check for closed or partially closed valves before/after heater
• Listen for normal operation sounds (burner flame, compressor running)

When to Call Professional: Heat exchanger cleaning requires disassembly and acid washing. Gas pressure testing requires specialized equipment. Don't attempt yourself—contact our certified technicians.

Problem #3: Heater Turns Off Too Soon (Short Cycling)

Possible Causes:

• Dirty filter causing flow restriction: Most common cause
• Faulty high-limit switch: Safety switch shuts down heater prematurely
• Oversized heater: Heater too powerful for pool size
• Low water flow: Pump issues or plumbing restrictions
• Bad pressure switch: Sensing incorrect water pressure

DIY Troubleshooting:

• Clean or replace pool filter
• Check filter pressure gauge (should be 10-25 PSI when clean)
• Verify all valves are fully open
• Ensure skimmer and pump baskets are empty

When to Call Professional: If filter cleaning doesn't resolve the issue, high-limit switches and pressure switches require testing and possible replacement.

Problem #4: Heater Makes Strange Noises

What Different Sounds Mean:

• Rumbling or roaring (gas heaters): Scale buildup on heat exchanger—needs professional cleaning
• Clicking or ticking: Usually normal thermal expansion—if excessive, check for loose parts
• Whistling or hissing: Gas leak (EMERGENCY—shut down immediately) or air in system
• Grinding or rattling: Fan motor bearings failing or loose components
• Banging when shutting off: Water hammer—may need expansion tank or check valve

When to Call Professional: Any abnormal sounds warrant inspection. Rumbling indicates dangerous scale buildup that can crack the heat exchanger. Never ignore gas-related sounds.

Problem #5: Pilot Light Won't Stay Lit (Gas Heaters)

Common Causes:

• Dirty pilot orifice: Debris or spider webs blocking pilot
• Faulty thermocouple: Safety sensor not detecting pilot flame
• Low gas pressure: Insufficient gas to maintain pilot
• Wind or drafts: Outdoor installations affected by weather

DIY Troubleshooting:

• Follow manufacturer's pilot lighting instructions carefully
• Ensure you're holding pilot button for full 30-60 seconds
• Check for spider webs or debris near pilot (very common in Florida)

When to Call Professional: Thermocouple replacement requires gas line work. If pilot won't stay lit after 2-3 attempts, call professionals. Repeated attempts can flood gas into the combustion chamber (dangerous).

Problem #6: Electric Heat Pump Icing Up

Why It Happens:

Electric heat pumps pull heat from the air. In Florida winter mornings when air temperature drops below 50°F, the evaporator coils can freeze, blocking airflow and preventing heating.

Solutions:

• Allow ice to melt naturally (turn off heater, wait 2-4 hours)
• Check that fan motor is running (no airflow causes icing)
• Clean coils—dirty coils restrict airflow and promote icing
• Verify refrigerant levels (low refrigerant causes icing)

When to Call Professional: Refrigerant service requires EPA-certified technicians. Recurring icing indicates a system problem requiring diagnosis. Our heat pump specialists service all major brands.

Florida-Specific Heater Considerations

Winter Heating Season (December-March)

Florida's "winter" is prime pool heating season. Water temperatures drop to 55-65°F without heating, making pools uncomfortable. This is when heaters work hardest and when most failures occur. Heater demand in Orlando and Davenport peaks from late December through February.

Seasonal Heater Tune-Ups

Best time to service your heater: October-November (before peak heating season)

• Professional cleaning of burners and heat exchanger
• Testing of all safety switches and sensors
• Gas pressure and flame verification
• Electrical connection inspection
• Refrigerant charge check (heat pumps)

Annual maintenance prevents 80% of mid-winter heater failures. Our maintenance customers rarely experience unexpected breakdowns. Ask about our comprehensive equipment warranty program that includes annual heater service.

Salt Water Pool Considerations

Salt water systems are highly corrosive to pool heaters. Heat exchangers in salt pools fail 30-40% faster than traditional chlorine pools. If you have a salt system:

• Install a sacrificial anode to protect heat exchanger
• Consider titanium heat exchangers (more expensive but last longer)
• Rinse heater with fresh water after each season
• Monitor for corrosion during annual service

Should You Repair or Replace Your Heater?

Repair if:

• Heater is less than 8 years old
• Repair costs less than 50% of replacement cost
• Only one component has failed (pressure switch, thermostat, etc.)
• Unit has been maintained regularly

Replace if:

• Heater is over 10 years old
• Heat exchanger is cracked or severely corroded
• Repair costs exceed 50% of replacement cost
• Multiple failures in past 2 years
• Energy efficiency has degraded significantly

Central Florida Pool & Spa offers free replacement quotes and specializes in energy-efficient equipment upgrades. Modern heaters heat 30-40% faster while using less energy. We handle all permits, installation, and warranty registration. Our equipment warranty coverage protects your investment.

Upgrade to Smart Pool Automation

Tired of heater failures catching you by surprise? Our smart pool automation systems monitor heater performance and alert you to problems before complete failure. You can also:

• Control heater remotely from your smartphone
• Schedule heating around your usage patterns (save energy)
• Receive alerts if heater fails to reach set temperature
• Monitor energy consumption in real-time

Automation integration starts at just $1,200 installed. Perfect for vacation homes, rental properties, or anyone who wants ultimate control over their pool system.

Conclusion

Pool heater problems are frustrating, but many issues have simple solutions. Start with the diagnostic checklist, check for obvious problems (power, water flow, settings), and know when to call professionals—especially for gas-related issues.

Central Florida Pool & Spa has serviced thousands of pool heaters over 25+ years. We offer same-day heater repair service throughout Central Florida, including Orlando, Davenport, and surrounding areas. Our 688+ five-star reviews reflect our commitment to fast, reliable heater service.

Don't let a broken heater ruin your swimming season. Contact us today for same-day diagnosis and repair. Most heaters repaired same-day or next-day!