Gas Piping - Lennox LHT078H Installation Instructions Manual

6- Make sure the cap over the unit bottom drain hole is
secure.
7- Rotate the drain pan until the downward slope is
toward the back of the unit. Slide the drain pan back
into the unit. Be careful not to dislodge the cap over
the bottom drain hole.
8- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
9- Replace the condensate drain mullion and reinstall
eight screws.
10- Reinstall filter door on hinges.
Bottom Drain Connection
1- Open blower and heat access doors. See figure 5.
2- Remove six screws from filter access door. Refer to
figure 6.
3- Open filter access door hinges and carefully remove
door.
4- Remove eight screws holding condensate drain
mullion and remove mullion.
5- Lift front edge of the drain pan (to clear bottom drain
plug) and slide drain pan out of unit. See figure 7.
6- Turn the drain pan upside down and drill a pilot hole
through the bottom of the drain pan in the center of
the coupling. See figure 8.
BOTTOM CONDENSATE DRAIN
CAUTION: Be careful not to
damage the coupling threads
when drilling the hole.
After drilling the pilot
hole, drill a 7/8" hole from
the inside of the pan.
FIGURE 8
DRILL A PILOT
HOLE IN CENTER
OF COUPLING
Page 9
7- From the inside of the pan, use a Vari-Bit
enlarge the hole to 7/8". Do not damage coupling
threads.
8- Remove the cap over the unit bottom drain hole.
9- Slide the drain pan back into the unit.
10- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
11- From the front side of the unit, move the drain pan
until the bottom coupling settles into the unit bottom
drain opening. Once in place, check to make sure the
coupling is still positioned through the rear
condensate drain hole.
12- Use a field-provided 1" plug to seal side drain
connection.
13- Replace the condensate drain mullion and reinstall
eight screws.
14- Reinstall filter door on hinges.
Connect Gas Piping (Gas Units)
Before connecting piping, check with gas company or
authorities having jurisdiction
requirements. When installing gas supply piping, length
of run from gas meter must be considered in determining
pipe size for 0.5" w.c. (.12kPa) maximum pressure drop.
Do not use supply pipe smaller than unit gas connection.
For natural gas units, operating pressure at the unit gas
connection must be a minimum of 4.7" w.c. (1.17kPa)
and a maximum of 10.5" (2.60kPa) w.c. For LP/propane
gas units, operating pressure at the unit gas connection
must be a minimum of 10.5" w.c. (2.61kPa) and a
maximum of 13.0" w.c. (3.23kPa).
When making piping connections a drip leg should be
installed on vertical pipe runs to serve as a trap for
sediment or condensate. A 1/8" N.P.T. plugged tap is
located on gas valve for test gauge connection. Refer to
Heating Start-Up section for tap location. Install a ground
joint union between the gas control manifold and the main
manual shut-off valve. See figure 9 for gas supply piping
entering outside the unit. Figure 10 shows bottom gas
entry piping through the curb. Figure 11 shows bottom
gas entry piping through the unit.
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquified petroleum gases.
® bit to
for local code