F11 False flame signal

What the control is telling you

Control sees flame when it is not asking the boiler to run. 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 valve leaking through
• Spark igniter or flame rectifier probe faulty
• Condensate backup into the combustion chamber
• Refractory wall touching the probe

Test and repair steps

1. Look in the sight window if there is flame, shut the gas at the service valve and replace the gas valve
2. If the flame signal is above 1.0 with the burner off, replace the spark igniter and the flame rectification probe
3. If the signal disappears with the gas off, check the gas valve electrical connection
4. Check for condensate backup and repair; replace a damaged refractory wall
5. A refractory wall resting on the probe can ground the signal and give a false reading
6. Turn the gas back on after repairs

Models that show this code

12 models in Elite EL

Other codes on the same units

• F05 Supply temperature high
• F06 Return temperature high
• F09 No flame on ignition
• F10 Flame loss
• F13 Fan speed error
• F20 Condensate full
• F31 Program error
• CASCADE MASTER READY Cascade master ready