33
Ignition Failed displayed on screen
Hold 109: Ignition failed
An ignition error occurs when 3 consecutive attempts at lighting the burner have failed. This is a manual reset error where the
technician must press OK to clear the error.
Check for constant spark for 6
seconds across spark igniter
NO
YES
Adjust igniter gap to
3/16” and/or clean
igniter
Check incoming gas pressure is
between 3” and 14” w.c.
NO
Check regulator for
proper static incoming
gas supply pressure
YES
Turn high fire screw counter-
clockwise ¼ turn at a time
NO
Verify gas valve is
being powered by
ignition control
Check ignition speed is between
2500 to 3000 RPM using
System Monitor
NO
Adjust ignition speed
to 3000 RPM
YES
YES
Burner lights off and stays on
NO
Check flame sensor
for carbon deposits,
and clean if
necessary
NO
Position flame sensor
so that it is closer to
the burner
YES
Adjust high fire combustion to
8.5 – 9.0% CO
2
NO
CO
2
< 8.5%
Turn high fire screw
counter-clockwise
NO
CO
2
> 9.0%
Turn high fire screw
clockwise
YES
Adjust low fire combustion to
8.0 – 8.5% CO
2
NO
CO
2
< 8.0%
Turn low fire screw
clockwise
NO
CO
2
> 8.5%
Turn low fire screw
counter-clockwise
YES
Recheck high-fire combustion:
8.5 – 9.0% CO
2
NO
Replace igniter and
graphite igniter
gasket
