60
SERVICING
S-314 CHECKING FLAME SENSOR
A flame sensing device is used in conjunction with the ig-
nition control module to prove combustion. If proof of flame
is not present the control will de-energize the gas valve
and "retry" for ignition or lockout.
WARNING
HIGH
VOLTAGE
D
ISCONNECT
ALL
POWER BEFORE SERVICING OR
INSTALLING THIS UNIT.
M
ULTIPLE POWER SOURCES MAY
BE PRESENT.
F
AILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
Flame signal is continuously monitored by the IFC. The
flame rod, flame rod wire, and proper grounding are all
critical to proving the presence of flame. Because of the
design of the Honeywell flame proving system, reading
flame signal with a microamp meter will not provide reli-
able and consistent results and is therefore not a recom-
mended practice. The IFC has a built in warning (E6) if
flame signal is approaching the low threshold.
NOTE:
Contaminated fuel or combustion air can create a
nearly invisible coating on the flame sensor. This coating
works as an insulator causing a loss in the flame sense
signal. If this situation occurs the flame sensor must be
cleaned with steel wool.