Trane A801X026AM2SC Installation, Operation And Maintenance Manual page 56

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
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.
56
3.2 Fault Code
Cycle power to the furnace
and call for 1
PS1 is closed
Yes
& is good
PS1 is closed & is
NO
good
Verify PS hose(s) is connected, and
that flue piping has no obstruc on.
st
stage heat.
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
Note #1
24 volts = Open Switch
0 volts = Closed Switch
Note #2
Measured pressure is
nega ve, greater than refers
to magnitude only.
A801X measure BK to WH at the
inducer motor and
IND-H – IND-N at IFC
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.
A801X-SVX001-1A-EN
**
Replace inducer
assembly