2.2 Fault Code
Cycle power to
furnace and call for
heat
Is manifold pressure
~3.5"WC (NG)
~10.0" WC (LP)
**
Adjust manifold gas pressure to
~3.5"WC (NG)
~10.0" WC (LP)
Check opera!on
**
NO
NO
YES
Is minimum outlet
gas manifold
pressure
maintained?
DEFINITION
RECYCLE Lock Out = 10 recycles within a single
call for heat. Lockout period is for one hour.
Flame is sensed & then lost
Disconnect electrical
power to furnace.
Connect manometer
to manifold pressure
connector
NO
YES
NO
Disconnect electrical
power to furnace.
Connect manometer to
inlet gas pressure
connector
Cycle power to
furnace and call for
heat
Is minimum outlet
gas manifold
pressure
maintained?
Correct incoming
gas supply pressure
NOYES
Turn all gas
appliances on
Possible Causes
Dirty Sensor
Dirty burners
Poor grounding
Sensor loca!on
Wire connec!ons
Measure flame current. Is
flame current greater
than 0.75 micro-amp?
(0.75-3 µA = Normal)
Possible Causes
Plugs
Blower door
Wind gust
Power interrupt
YES
Possible Causes
Plugs
Blower door
Wind gust
Power interrupt
There are two flame sense pads located on the IFC,
marked “FP”. To measure flame current, use a VOM set
to DC volts. Flame current will vary depending on the
type of meter used. Typical flame current ranges from
0.75 – 3.0 micro-amps (0.75 – 3.0 VDC)
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