F10 Flame loss

What the control is telling you

Flame was lost three times during one demand call. Lockout with pump on. Control: FAULT light red steady and LOCKOUT shown on lower line; reset with RESET held over 1 second after repair.

Applies to: EL-80, EL-110, EL-150, EL-220, EL-299, EL-399 (N/LP)

Likely causes

• Gas pressure dropping during operation
• Unstable flame
• Flame rectifier or spark probe dirty/worn
• Burner or burner door gaskets leaking

Test and repair steps

1. Watch the gas pressure while the boiler runs
2. Make sure the flame is stable
3. See that the display goes from GAS VALVE ON to RUN within a few seconds of lighting
4. Check the FLAME signal in the status menu: above 1.0 microamp while firing
5. If under 1 microamp clean the flame rectifier and spark probe; if still low replace both
6. Flame signal should be steady after 1 minute at about 5.0 to 9.0; if not, take the burner door apart and check the burner and gaskets

Models that show this code

12 models in Elite EL

Other codes on the same units

• F04 Flue sensor failure
• F05 Supply temperature high
• F06 Return temperature high
• F09 No flame on ignition
• F11 False flame signal
• F13 Fan speed error
• F20 Condensate full
• F31 Program error