Venting - Lennox MERIT Series Installation Instructions Manual

Venting

A 4-inch diameter flue transition is factory-installed on
the combustion air inducer outlet of all models. Figure 16
shows the combustion air inducer as shipped from the fac-
tory.
Mounting Screws Location
Flue Transition
Figure 15
UPFLOW POSITION
Top Vent Discharge
Flue
Transition
Pressure
Switch
Make-Up
Box
Figure 16
IMPORTANT
The unit will not vent properly with the flue transition
pointed down in the 6 o'clock position. The combustion
air inducer may be rotated clockwise or counterclockwise
by 90° to allow for top or side vent discharge in all
applications. When the unit is installed, the flue transition
must be in the 9 o'clock, 12 o'clock or 3 o'clock position.
If necessary, reposition the combustion air inducer, pres-
sure switch and/or make-up box as needed per the follow-
ing steps. See figures 17 through 21.
Mounting Screws
Vent Pipe
Collector Box
FLOW
AIR
1 - Remove the four mounting screws (figure 15) which
secure the combustion air inducer / pressure switch
assembly to the orifice plate. Lift the assembly and
rotate it 90 degrees clockwise or counterclockwise
to either the 3 o'clock position or to 9 o'clock
position. Resecure with four screws. Gasket should
be left in place.
2 - Use tin snips to cut preferred opening on the cabinet
for repositioning the flue outlet. Use the cut-out piece
as a cover plate to patch unused opening on cabinet
.
Cover Plate
Pressure
Switch
Vent Pipe
Flue
Transition
Gas supply piping must be brought into the unit from the right
side in order to accommodate the flue pipe.
ference with inducer motor
Remove make-up box assembly (2 screws) and cut wire tie to
free make-up box wires. Re-install make-up box on other side
of cabinet.
Re-secure make-up box wires: Either pull excess wires
through the blower compartment and secure using supplied
wire tie, or coil excess wire and secure to the gas manifold.
Collector Box
Pressure
Switch
Make-Up
Box
Cut combustion air inducer tubing from 9" to 5" to avoid
interference with inducer motor
Page 13
UPFLOW POSITION
Left Side Vent Discharge
Collector Box
FLOW
AIR
Figure 17
UPFLOW POSITION
Right Side Vent Discharge
Flue Transition
Cover Plate
FLOW
AIR
Figure 18
Make-Up
Box
Vent Pipe