PG92MSA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
59
Checklist
• Put away tools and instruments. Clean up debris.
• Check Input/Output gas pressure
• Check heat rise per application static pressure
• Cooling CFM per application static pressure
• Verify that blower-OFF delay time is selected as desired.
• Verify that blower and burner access doors are properly installed.
• Cycle test furnace with room thermostat.
• Check operation of accessories per manufacturer’s instructions.
• Review User’s Guide with owner. 
• Attach literature packet to furnace
.
SERVICE AND MAINTENANCE PROCEDURES 
Untrained  personnel  can  perform  basic  maintenance  functions  such  as
cleaning and replacing air filters. All other operations must be performed
by trained service  personnel. A  qualified service person should inspect
the furnace once a year.
GENERAL
These instructions are written as if the furnace is installed in an upflow
application.  An  upflow  furnace  application  is  where  the  blower  is
located  below the  combustion and  controls section  of the  furnace, and
conditioned air is discharged upward. Since this furnace can be installed
in  any  of  the  4  positions  shown  in  Fig. 2,  you  must  revise  your
orientation to component location accordingly. 
ELECTRICAL CONTROLS AND WIRING
The  electrical  ground  and  polarity  for  115-V  wiring  must  be  properly
maintained. Refer to Fig. 33 for field wiring information and to Fig. 62
for furnace wiring information.
NOTE: If the polarity is not correct, the STATUS LED on the control
will flash rapidly and Status code (10.1 ) is displayed. This will prevent
the  furnace  from  heating.  The  control  system  also  requires  an  earth
ground for proper operation of the control and flame-sensing electrode. 
The  24-V  circuit  contains  an  automotive-type,  3-amp.  fuse  located  on
the  control  (see  Fig. 38).  Any  shorts  of  the  24-V  wiring  during
installation, service, or maintenance will cause this fuse to blow. If fuse
replacement is required, use ONLY a 3-amp. fuse. The control LED will
display status code (24.1) when fuse needs to be replaced. 
Proper  instrumentation  is  required  to  service  electrical  controls.  The
control  in  this  furnace  is  equipped  with  a  Status  Code  LED
(Light-Emitting  Diode)  and  Major/Minor  3  digit  codes  to  aid  in
installation, servicing, and troubleshooting. Status codes can be viewed
at  the  sight  glass  in  blower  access  door. The  furnace  control  LED  is
either ON continuously, rapid flashing, or a code composed of 2 digits.
The  major  status  code  is  displayed  on  the  LED  indicator  through  the
door with the first digit being the number of short flashes and the second
digit  being  the  number  of  long  flashes.  The  major  status  code  is
displayed  in  the first  2  digits  of  the  display.  The minor  status  code  is
displayed in the third digit. 
For  an  explanation  of  status  codes,  refer  to  service  label  located  on
blower access door, or Fig. 61 and the troubleshooting guide by scanning
the QR code or see Fig. 72 for a brief Troubleshooting Guide. 
Retrieving Stored Fault Codes
The  stored  status code  will not be erased  from  the  control memory,  if
115-V or 24-V power is interrupted. See the Service Label, Fig. 61 for
more information.
1. To retrieve the last 7 fault codes, proceed with the following: 
NOTE:  NO  thermostat  signal  may  be  present  at  control,  and  all
blower-OFF delays must be completed.
a. Leave 115-V power to furnace turned on.
b. Remove access door.
c. Depress blower door switch to energize the control board.
WARNING
!
FIRE, INJURY OR DEATH HAZARD
Failure  to  follow  this  warning  could  result  in  personal  injury,  death
and/or property damage. 
The ability to properly perform maintenance on this equipment requires
certain knowledge, mechanical skills, tools, and equipment. If you do
not  possess  these,  do  not  attempt  to  perform  any  service  and
maintenance  on  this  equipment  other  than  those  procedures
recommended in the Owner’s Manual.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental pollution.
Remove  and recycle  all  components or  materials (i.e.  oil,  refrigerant,
control board, etc.) before unit final disposal.
CAUTION
!
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper furnace operation
or failure of furnace. 
Label all wires prior to disconnection when servicing controls. Wiring
errors can cause improper and dangerous operation. 
WARNING
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death,
or property damage. 
Before  installing,  modifying,  or  servicing  system,  main  electrical
disconnect switch must be in the OFF position and install a lockout tag.
There  may  be  more  than  one  disconnect  switch.  Lock  out  and  tag
switch  with  a  suitable  warning  label.  Verify  proper  operation  after
servicing. Always  reinstall  access  doors  after  completing  service  and
maintenance.
WARNING
!
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or death.
There may  be  more  than  one  electrical  supply  to  the  furnace.  Check
accessories and cooling unit for additional electrical supplies that must
be shut off  during  furnace servicing.  Lock out and  tag  switch  with  a
suitable warning label.