Zodiac pool heater displays E13; heater may shut down during operation, especially in windy conditions.

Critical safety: A tripped rollout switch indicates flames leaving the combustion chamber. Turn off power and gas immediately. Do not bypass the rollout switch.

• Inspect rollout switch: Locate the manual reset rollout switch near the burner area. If it has a reset button, press it once after the heater has cooled. If it trips again, stop and investigate further.
• Check for obstructions: Remove the burner access panel and inspect for debris, nests, or rust blocking the burners or combustion chamber. Clean carefully.
• Examine heat exchanger: Look for heavy soot or signs of blockage at the exchanger fins. A blocked exchanger can cause flames to roll out. This typically requires professional cleaning or replacement.
• Assess venting and wind: Ensure the vent termination meets Zodiac guidelines and is not subject to strong downdrafts. Correct venting issues before reuse.
• Replace rollout switch if damaged: If the switch shows signs of overheating or will not reset, replace it with the correct Zodiac rollout switch. Do not operate the heater until the root cause of rollout is resolved.