Gas Piping - Lennox LGT036 Installation Instructions Manual

3- Make sure the cap over the unit bottom drain hole is
secure.
4- 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.
5- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
6- Replace the condensate drain mullion.
Bottom Drain Connection
1- Remove the condensate drain mullion. See figure 7.
2- Lift the front edge of the drain pan and slide pan out
of unit. See figure 9.
3- 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 10.
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 10
4- From the inside of the pan, use a Vari-Bit
enlarge the hole to 7/8". Do not damage coupling
threads.
5- Remove the cap over the unit bottom drain hole.
6- Slide the drain pan back into the unit.
7- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
8- 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.
9- Use a field-provided 3/4" plug to seal side drain
connection.
10- Replace the condensate drain mullion.
DRILL A PILOT
HOLE IN CENTER
OF COUPLING
bit to
®
Page 8
Connect Gas Piping (Gas Units)
Before connecting field-provided piping, check with gas
company or authorities having jurisdiction for local code
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.
Operating pressures at the unit gas connection must be
as shown in table 1.
TABLE 1
OPERATING PRESSURE AT GAS CONNECTION "w.c.
Natural Gas
Min.
036-072 4.5
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 11 for gas supply
piping entering outside the unit. Figure 12 shows
complete bottom gas entry piping.
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquified petroleum gases.
Do not use Teflon® tape to seal gas piping. Use a
moderate amount of pipe compound on the gas pipe only.
Make sure the two end threads are bare.
CAUTION
If a flexible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe
shall be installed at the gas valve and extend out­
side the furnace cabinet.
WARNING
Do not exceed 600 in-lbs (50 ft.-lbs) torque when at­
taching the gas piping to the gas valve.
IMPORTANT
Compounds used on threaded joints of gas piping
must be resistant to the actions of liquified petro­
leum gases.
LGT/LCT036, 048, 060, 072
LP / Propane Gas
Max. Min. Max.
10.5 11 13