Trane DH1B040A9241C Series, Сервисные данные

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UH1-DH1-SF-1L
Service Facts
19
NO
YES
YES
Is pressure greater
than pressure
switch label?
See Note #2
Replace pressure switch.
Check operation.
Is the inducer
motor running?
NO
Is 120 volts
measured between
the IFC IND-H to
IND-N?
Is 24 volts present,
measured across PS
(orange to yellow)?
See Note #1
NO
NO
YES
Replace IFC.
Check operation.
Check PS hose,
flue piping for
obstruction and/or
confirm vent size
is correct
Pressure switch is
okay
Disconnect electrical
power from the furnace
and remove 1 wire from
the pressure switch
Is continuity
measured
across PS?
Replace pressure
switch. Check
operation.
YES
Pressure switch is okay.
Re attach wire to PS
NO
Note #1
24 volts = Open Switch
0 volts = Closed Switch
DEFINITION
An error has occurred with the P.S.
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
Note #2
Measured pressure is
negative, greater than
refers to magnitude only.
3 Flash Fault LED
Cycle power to
furnace and call for
heat.
NO
Is TCO-B
open?
Disconnect electrical
power from the furnace
and check TCO-B
YES
Allow time for Inducer
Limit to cool and
investigate cause for high
vent temperatures.
Is Inducer Limit
cool and
contacts open?
Replace Inducer
Limit switch
YES
NO
Replace Inducer.
Check operation.
YES