A pool heater not working cuts your swim season short in a hurry. DFW pool owners depend on heaters for spring and fall swimming, and when yours quits, comfortable water temps go with it. The good news is that a lot of heater issues trace back to something simple. This pool heater troubleshooting guide covers gas heaters, heat pumps, and electric units — because the diagnosis is different for each.
Gas Pool Heater Won’t Ignite
When your pool heater won’t ignite, start with gas supply. Confirm the gas valve to the heater is open, and check if other gas appliances in the house work — that confirms gas is flowing. If you smell gas near the heater, shut off the supply immediately and call your gas company. The American Gas Association is clear: any suspected leak near outdoor equipment gets addressed before anything else.
Gas heaters still need electricity for ignition and controls, so check the breaker and GFCI. Then look at water flow — gas heaters have a flow switch that blocks firing when pressure is low. Usual causes: dirty filter restricting flow, pump not running, or valves partially closed. Clean the filter, confirm the pump is on, open everything up.
Listen when the heater tries to fire. You should hear clicking from the igniter. No click means a dead igniter — the most common gas heater repair in DFW, about $100 to $250 to replace. Click but no flame usually points to a gas valve issue or air in the line. Check error codes too — Pentair MasterTemp shows E05 for flue sensor, E01 for ignition failure. Hayward Universal displays IF for ignition failure, AO/AG for temp sensors. The Pentair support page has model-specific code lookups. Our broken heater repair guide covers all of these scenarios.
Heat Pump Pool Heater Not Working
Heat pumps pull warmth from outdoor air, so the first question: is it warm enough? They lose effectiveness below 50°F and basically stop producing useful heat under 40°F. On a cold DFW morning, that’s not a malfunction — it’s the technology’s limit. The U.S. Department of Energy has a good breakdown of operating ranges.
If temp is fine but no heat, check the fan on top — should be spinning when the unit runs. No fan means motor failure, dead capacitor, or control board issue. Then check the evaporator coils. DFW pollen buries them from March through May — hose them off gently, never pressure wash. Make sure the unit has 2 to 3 feet of clearance on all sides, because fences and landscaping choke airflow. In cold weather, heat pumps cycle into defrost mode periodically — that’s normal. Stuck in defrost? That’s a failed defrost board. Our heat pump repair page covers what we see most often.
Electric Pool Heater Not Working
Electric heaters are simpler. Check breaker and GFCI, verify the thermostat setting wasn’t bumped, and look for a high-limit reset button on the unit — it trips when the heater overheats. If none of that works, the heating element has likely failed. Our pool electrical repair team handles all electric heater service across DFW.
Heater Running But Water Still Cold
This one is maddening. Common causes: the heater is undersized for your pool volume, you’re not using a solar cover and losing heat through evaporation overnight, or the diverter valve is routing heated water to the spa instead of the pool. The Department of Energy estimates covers reduce heat loss by up to 70%. Also watch for heat exchanger scaling from DFW’s hard water — it reduces heat transfer efficiency over time. Thermostat calibration can drift too, making the heater think it’s hit the target temp when it hasn’t.
People Also Ask
Why won’t my pool heater ignite?
Usually a tripped igniter, no gas flow, low water pressure, or a tripped breaker cutting the ignition circuit. Our heater repair guide walks through every cause.
How do I troubleshoot a pool heat pump?
Check outdoor temperature, verify the fan is running, clean the coils, and confirm airflow clearance around the unit. If it’s stuck in defrost mode, call for service.
How much does pool heater repair cost?
Igniter replacement runs $100 to $250. Control board repair costs $200 to $400. Heat exchanger replacement is $500 to $1,500+ depending on the unit. HomeAdvisor’s pool cost data has wider pricing ranges by region.
Why is my pool heater running but the water is still cold?
Undersized heater, no solar cover, diverter valve in the wrong position, scaled heat exchanger, or a miscalibrated thermostat. A professional assessment pinpoints it fast.
PoolBurg Heater Repair — All Types, All Brands
Gas, heat pump, or electric — if your pool heater not working has you stuck, contact PoolBurg for same-day diagnostics when possible. We’ll tell you straight whether it’s a repair or a replace, no runaround.
