Trane S8V2A040M3PC Installation, Operation And Maintenance Manual page 63

DEFINITION
An error has occurred with the PS1, indica ng that the pressure
switch is closed when it should be open.
In most cases, the pressure switch is not the problem.
NOTE: Verify pressure switch wiring and tube
rou ng are correct.
DEFINITION
An error has occurred with the PS1 indica ng that the pressure
switch is either open when it should be closed.
In most cases, the pressure switch is not the problem.
NOTE: Verify pressure switch wiring and tube rou ng
are correct.
PS1 Open errors can occasionally occur when wind
gusts occur. The IFC will a empt to close both PS1
nd
and PS2 and operate on 2 stage during such an
event.
S8V2-SVX001-1A-EN
3.1 Fault Code
Cycle power to the furnace
Replace pressure
NO
switch
Cycle power to the furnace
and call for 1
PS1 is closed
Yes
Pressure Switch is
NO
okay.
PS hose, flue piping for obstruc on
and/or confirm vent size is correct
st
and call for 1 stage heat.
Is 24 volts present ,
measured across PS1
YES
( orange to yellow)?
See Note #1
3.2 Fault Code
st
stage heat.
NO
Is the inducer
NO
motor running?
YES
Does the igniter
glow within 60
Verify no voltage at IFC at
seconds?
NO
Is 24 volts present,
measured across PS1
(orange to yellow)?
See Note #1
YES
Is pressure greater
than pressure switch
YES
label?
See Note #2
NO
Possible Causes
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
Note #1
24 volts = Open Switch
0 volts = Closed Switch
Verify wiring. If
correct, replace IFC
Note #1
24 volts = Open Switch
0 volts = Closed Switch
Note #2
Measured pressure is
nega ve, greater than refers
to magnitude only.
Is ~120VAC measured
from RD to WH on the
YES
inducer motor within
60 seconds of the W1
call?
NO
IND-LO - IND-N
Replace IFC
Replace pressure switch.
Check opera on.
Replace inducer
assembly
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