Trane A952V040BU3SB Installation, Operation And Maintenance Manual page 103

DEFINITION
RETRY Lock Out = 3 unsuccessful tries for igni on
within a single call for heat. Lockout period is for
one hour
Flame has never been sensed
All gas appliances in the home should be turned
on to verify gas pressure
Possible causes:
Burner alignment
NO
Dirty burners
Low manifold pressure
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)
A952V-SVX001-1B-EN
Is inlet gas pressure above
YES
13.8" WC or less than
nameplate minimum ?
NO
Cycle power to furnace.
Connect manometer to
manifold pressure
st
connector and call for 1
stage heat
NO
Is manifold pressure
Does gas ignite? ~1.7"WC (NG)
YES
Do all burners
ignite within 4
seconds?
posi on and correct
if needed. Check
YES
Measure flame
current. Is flame
YES
current less than 0.5
micro-amp?
NO
Flame sensor is good
2.1 Fault Code
Disconnect electrical
power to furnace.
Connect manometer
to inlet gas pressure
connector
Correct inlet gas pressure.
Maximum pressure is 13.8"WC
Check opera on
Possible causes
Is any gas
Switch OFF?
pressure NO
No voltage to GV
present?
Debris in gas valve
YES
NO
~6.0"WC (LP)
YES
Check igniter
opera on
Possible Causes
Dirty Sensor
Dirty burners
Poor grounding
Sensor loca on
Wire connec ons
T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g
Adjust manifold gas pressure to
~1.7"WC (NG)
~6.0"WC (LP)
Check opera on
103