Heater will not start; display shows E01 shortly after power-up

Safety first: Turn OFF power at the breaker and close the gas supply valve before opening the heater. Allow the unit to cool completely.

• Check gas supply: Verify the gas valve to the Poolworld heater is fully open and that other gas appliances in the home work normally. If gas supply is questionable, contact your gas provider.
• Inspect burner flame: Remove the front panel. Restore power and call for heat while observing through the sight glass. The flame should be steady and blue. If it is weak, yellow, or lifting, shut power off and clean the burner tray and orifices.
• Clean the flame sensor: With power and gas OFF, locate the flame sensor rod near the burner. Remove the mounting screw, pull out the rod, and gently clean it with fine emery cloth or a Scotch-Brite pad until shiny. Do not sand excessively. Reinstall and ensure the rod is fully in the flame path.
• Check wiring: Inspect the flame sensor lead and connector at the ignition control board for corrosion, loose fit, or damage. Reseat the connector firmly.
• Reset and test: Restore gas and power, clear the error by cycling power, and call for heat again. If E01 returns after cleaning and verifying gas supply, the ignition control board or flame sensor may need replacement.

Warning: If you smell gas or see signs of soot or flame rollout, shut the heater down and contact a qualified technician immediately.