Heater shows ROL or rollout error and will not fire.

Critical safety: A rollout condition can indicate dangerous combustion problems. Turn off gas and power immediately. Do not reset repeatedly without finding the cause.

• Inspect rollout switch: Locate the flame rollout switch near the burner compartment. Some are manual reset; press the reset button if present. If it trips again, stop and call a professional.
• Check for soot: Look for black soot around the burner area or vent. This indicates poor combustion and requires professional cleaning and adjustment.
• Vent and air: Ensure the heater has adequate clearance and ventilation. Check for blocked exhaust or intake.
• Replace rollout switch: If the switch is physically damaged or will not reset, replace it with the correct Jandy rollout switch, but only after resolving the underlying cause.