16. Check furnace operation through 2 complete heat operating
cycles. Look through sight glass in burner enclosure to check
burners. Burner flames should be clear blue, almost transpar-
ent. (See Fig. 9.)
17. Check for gas leaks.
Never use matches, candles, flame, or other sources of
ignition to check for gas leakage. Use a soap-and-water
solution. Failure to follow this warning could result in a fire,
personal injury, or death.
18. Replace main furnace door.
SECONDARY HEAT EXCHANGERS
NOTE: The condensing side (inside) of the secondary heat
exchangers CANNOT be serviced or inspected. A small number of
bottom outlet openings can be inspected by removing the inducer
Fig. 8—Furnace Pressure and Drain Tubing Diagram
A00351
Furnace is shipped from factory in upflow configuration. Pressure tube and drain tube routing MUST match the diagrams below.
Tube location when used in DOWNFLOW application
Tube location when used on
HORIZONTAL - RIGHT application
Condensate Trap; Factory Installed
in Blower Shelf
Condensate Trap on
RIGHT Side
Condensate Trap on
LEFT Side
Tube location when used in UPFLOW application
Tube location when used on
HORIZONTAL - LEFT application
(Blower access panel removed)
1. All tubing must be connected securely and routed to avoid kinks and traps.
2. Pressure tubing must always slope away from pressure switch to collector box connection as shown.
3. HORIZONTAL-LEFT installations require the collector box pressure tube to be relocated between the inducer housing and
the blower shelf to prevent a trap.Refer to the Installation Instructions for further details.
NOTE:
325400-201 REV. C
(LIT - BOTTOM)
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX
DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX DRAIN TUBE
(BLUE)
INDUCER HOUSING (MOLDED) DRAIN TUBE
(BEHIND COLLECTOR BOX DRAIN TUBE)
FIELD-INSTALLED
FACTORY-SUPPLIED DRAIN TUBE
COUPLING (LEFT DRAIN OPTION)
FIELD-INSTALLED FACTORY-
SUPPLIED DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1/2-IN. CPVC STREET
ELBOWS (2) FOR LEFT
DRAIN OPTION
FIELD-INSTALLED
FACTORY-SUPPLIED DRAIN
TUBE COUPLING (RIGHT
DRAIN OPTION)
COLLECTOR BOX TUBE (GREEN)
CONDENSATE TRAP
CAP
PLUG
PLUG
CAP
COLLECTOR BOX
DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX DRAIN TUBE
(BLUE)
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
CONDENSATE TRAP
COLLECTOR BOX TUBE
(GREEN)
Condensate Trap on LEFT
Side Optional
CAP
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX TUBE (GREEN)
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX
EXTENSION TUBE
CONDENSATE TRAP
INDUCER HOUSING DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
PLUG
PLUG
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX TUBE
(GREEN)
CONDENSATE TRAP
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX EXTENSION
DRAIN TUBE
DRAIN TUBE
COUPLING
CAP
GAS VALVE
DRAIN TUBES ROUTED IN
FRONT OF GAS VALVE
PLUG
CAP
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
CONDENSATE TRAP
COLLECTOR BOX EXTENSION DRAIN TUBE
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR
BOX TUBE
(GREEN)
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
COLLECTOR BOX TUBE (PINK) RELOCATE TUBE BETWEEN BLOWER SHELF AND
INDUCER HOUSING FOR 040,060, AND 080 HEATING INPUT FURNACES
DRAIN TUBE
COUPLING
COLLECTOR BOX
DRAIN TUBE (BLUE)
AUXILIARY "J" BOX
RELOCATED HERE
CAP
PLUG
COLLECTOR BOX DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (GREEN)
COLLECTOR BOX TUBE (PINK)
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
COLLECTOR BOX
EXTENSION TUBE
CONDENSATE TRAP
INDUCER HOUSING DRAIN TUBE (VIOLET)
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
BURNER
ENCLOSURE
PRESSURE
REFERENCE
TUBE ASSEMBLY
BURNER
ENCLOSURE
PRESSURE
REFERENCE TUBE
ASSEMBLY
TUBE ROUTING
6