Condensate Drains; Connect Gas Piping; Pressure Test Gas Piping - Lennox LGH480 Installation Instructions Manual

Condensate Drain
Make drain connection to the 1" N.P.T. drain coupling
provided on unit. A trap must be installed between drain
connection and an open vent for proper condensate
removal. See figure 12. It is sometimes acceptable to drain
condensate onto the roof or grade; however, a tee should
be fitted to the trap to direct condensate downward. The
condensate line must be vented. Check local codes
concerning condensate disposal. Refer to pages 1 and 2
for condensate drain location.
CONDENSATE DRAIN CONNECTION
NOTE - Allow clearance to
open doors when installing
condensate piping.
Minimum Pitch
1" (25 mm) per
OPEN VENT
10' (3 m) of line
Á Á
Á Á Á Á
Á Á Á Á
Á Á Á Á
FIGURE 12

Connect Gas Piping

Two grommets are packaged with the flue exhaust and air
intake hoods located in the gas heat section. Grommets are
installed in the unit entry and gas heat division panel
knockouts. An additional grommet is required when routing
gas piping through the bottom of the unit.
Before connecting 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. For natural gas
units, operating pressure at the unit gas connection must
be a minimum of 6.0" w.c. (1.5kPa) and a maximum of 14"
(3.50kPa) w.c. For LP/propane gas units, operating
pressure at the unit gas connection must be a minimum of
11" w.c. (2.74kPa) and a maximum of 13.5" w.c. (3.36kPa).
507232-04 7/2017
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 13 for side entry gas
supply piping.
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquified petroleum gases.

Pressure Test Gas Piping

When pressure testing gas lines, the gas valve must be
disconnected and isolated. Gas valves can be
CAULK AROUND
damaged if subjected to more than 0.5 psig (3.5kPa).
CONDENSATE
See figure 14.
COUPLING
NOTE-Codes may require that manual main shut-off
UNIT
valve and union (furnished by installer) be installed in gas
line external to unit. Union must be of the ground joint
type.
After all connections have been made, check all piping
connections for gas leaks. Also check existing gas
MOUNTING
FRAME
connections up to the gas valve; loosening may occur during
installation. Use a leak detection solution or other preferred
means. Do not use matches candles or other sources of
ignition to check for gas leaks.
NOTE-In case emergency shut down is required, turn off
the main manual shut-off valve and disconnect main power
to unit. These devices should be properly labeled by the
installer.
Page 11
SIDE ENTRY OF GAS SUPPLY PIPING
GROUND
JOINT UNION
MANUAL MAIN
SHUT-OFF VALVE
TO GAS
SUPPLY
GAS PIPING
SUPPORT
FIGURE 13
(REFER TO
LOCAL CODES)
TO GAS
VALVE
DRIP LEG