Flash Fault Led - Trane *UH2B060A9V3VA Service Facts

DEFINITION
An error has occurred with the PS1 or PS2.
The error will be reported, indicating that the pressure switch
is either opened or closed, contrary to normal operating
sequence.
In most cases, the pressure switch is not the problem.
Note: Verify all wiring to pressure switch is
correct per wiring diagram
YES
While the furnace is operating on 1
nd
stage heat make a call for 2 stage
heat. Allow (30 seconds) for the
nd
furnace to transition to 2 stage.
YES
Is 24 volts present,
measured across PS2
(yellow/7 to brown)?
See Note #1
YES
Is pressure greater
than pressure
switch label?
See Note #2
Replace pressure switch.
NO
Check operation.
Check PS hose, flue piping
for obstruction and/or
confirm vent size is correct
X343070P08

3 Flash Fault LED

Cycle power to the furnace
and call for 1
st
Is 24 volts present,
Pressure measured across PS1
NO
switch is okay. (orange to yellow/6)?
Pressure
NO
switch is okay.
Is pressure greater
Check PS hose, flue piping for
obstruction and/or confirm vent
YES
st
stage heat.
Does the
furnace run on
st
1 stage?
NO
Disconnect electrical
Is the inducer power from the furnace
NO
motor running? and remove 1 wire from
each pressure switch
YES
See Note #1
YES
than pressure Replace pressure switch.
YES
switch label?
See Note #2
NO
size is correct
Is voltage measured at
inducer motor plug
between pins
NO
1 (BK) – 2 (RD)
2 (RD) – 3 (WH)
1 (BK) – 3 (WH)?
Replace or repair wiring
harness. Check operation.
Replace Inducer.
Check operation.
Service Facts
Note #1
24 volts = Open Switch
0 volts = Closed Switch
Note #2
Measured pressure is
negative, greater than refers
to magnitude only.
Is continuity
YES measured across
PS1 or PS2?
Replace pressure switch.
Check operation.
Pressure switches
are okay. Re attach
each wire to PS
Reconnect electrical
power to furnace. Cycle
Check operation.
power to furnace and call
st
for 1
See IFC Component Layout for
location of plug.
Is voltage measured at
IFC plug between pins
YES 1 (BK/6) – 2 (RD/6)
2 (RD/6) – 3 (WH/6)
1 (BK/6) – 3 (WH/6)?
Replace IFC.
Check operation.
YES
NO
stage heat.
NO
35