Heater Won't Ignite
Gas heaters that won't light may have a faulty igniter, gas valve issue, or pressure switch problem. Always check that gas is flowing and the pilot (if applicable) is lit before calling for service.
Water Not Reaching Set Temperature
If the heater runs but can't reach temperature, the heat exchanger may be scaled, the gas pressure may be low, or the unit may be undersized for your pool. BTU output decreases over time as components wear.
Pro Tip
For heat pumps, efficiency drops significantly below 50°F ambient temperature - this is normal, not a malfunction.
Strange Smells
A sulfur or rotten egg smell near a gas heater is dangerous - shut it off immediately and call a professional. Burning plastic or electrical smells also warrant immediate shutdown.
Error Codes
Modern heaters display error codes that indicate specific failures. Document the code and check your manual before calling for service - some codes indicate simple fixes like low water flow (often just a dirty filter).
Soot or Discoloration
Black soot on or around the heater indicates incomplete combustion - a serious issue that can produce carbon monoxide. This requires immediate professional attention.
Repair vs Replace
Heat exchangers cost $1,000-$2,500 to replace - often approaching the cost of a new unit. If your heater is over 8 years old and needs a major component, replacement is usually the better investment.