For downflow applications, horizontal supply and return duct
cover kits must be ordered from your distributor. Kit number
20464501PDGK is for the medium chassis and kit number
20464502PDGK is for the large chassis.
Cut insulation around the bottom openings and remove the
panels from the bottom of the unit, saving the screws holding the
panels in place.
A. Return air panel
B. Supply air panel
Install Flue Exhaust Hood
Install the flue exhaust hood, screen and lower flue hood prior to
operation of the unit.
To install the flue hood, screen and lower flue hood:
1. Remove the flue exhaust hood assembly box from the blower
2. Slide the screen over the flanges of the lower flue hood.
3. Slide the screen and lower flue hood assembly into the flue
Flue Exhaust Hood Assembly
A. Flue exhaust hood
4. Using the 3 screws provided, attach the flue exhaust hood
assembly, with the opening facing down, over the flue
exhaust opening in the utility panel. See "Hood Attachment"
D. Lower flue hood
Install Combustion Air Intake Hood
1. Locate the second hood.
2. Using the 3 screws provided, attach the combustion air
intake hood, with the opening facing down, to the heat
exchanger access door.
A. Flue exhaust hood
C. Lower flue hood
Connect Condensate Drain
The condensate drain outlet is a ³⁄₄" threaded PVC fitting located
at the bottom on the side of the unit. A ³⁄₄" drain line with trap
must be installed on all applications to avoid accumulation of
condensate under or around the unit.
Condensate Drain Connection
A ³⁄₄" (1.9 cm) NPT drain connection is supplied for condensate
piping. An external trap must be installed for proper condensate
A. Drain connection
B. 2" (5.1 cm) minimum
C. 3" (7.6 cm) minimum
Install ductwork in accordance with NFPA 90B and any local
The use of flexible, noncombustible connectors between the
main trunk ducts and the supply and return air plenums is
recommended to minimize vibration transmission.
Plenums must be individually sealed to the unit casing with
ducts terminating inside the structure.
D. Combustion air intake hood
E. Heat exchanger door
D. Positive liquid seal (required)
E. Flexible tubing, hose or pipe