Heater attempts to start but shuts down with E02; blower may run briefly, no sustained flame.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety Warning: Turn off electrical power and gas supply before opening the heater cabinet. Gas work beyond basic visual checks should be done by a licensed technician.
Basic checks:
- Check water flow and demand: Ensure the pool pump is running and the heater has a steady call for heat. Inadequate flow can cause unstable combustion.
- Inspect burner area: Remove the burner access panel. Look for rust flakes, spider webs, or debris on the burner tray and in the burner ports. Vacuum gently and use compressed air to clear the burner orifices (do not enlarge holes).
- Clean flame sensor: Remove the flame sensor rod (or combo igniter/flame sensor) and clean the metal rod with fine abrasive pad. Reinstall securely.
- Check venting: Verify that the flue outlet and intake (on sealed-combustion models) are not blocked by leaves, nests, or snow. Restricted venting can cause flame instability.
- Monitor operation: Restore power and gas, then start the heater. Watch through the sight glass: if the flame lights but drops out after a few seconds, the flame sensor or gas valve may be failing and should be tested by a technician.
Do not adjust gas pressure without proper tools and training; incorrect pressure can damage the heater or create a hazard.