Preliminary Seasonal Checks; Heating Start Up; Heating System Service Checks - Lennox 80MGF Series Manual

A−Preliminary and Seasonal Checks
1− Inspect electrical wiring, both field and factory installed
for loose connections. Tighten as required.
2− Check voltage at disconnect switch. Voltage must be
within range listed on the nameplate. If not, consult the
power company and have voltage condition corrected
before starting unit.
B−Heating Start-Up
1 − STOP! Read the safety information at the beginning
of this section.
2 − Set thermostat to lowest setting.
3 − Turn off all electrical power to appliance.
4 − This appliance is equipped with an ignition device
which automatically lights the burners. Do not try to
light the burners by hand.
5 − Remove access panel.
WARNING
Shock and burn hazard.
80MGF units are equipped with a direct spark igni-
tion system. Do not attempt to light manually.
6 − White Rodgers 36E Gas Valve −− Switch gas valve
lever to OFF. See figure 19.
Honeywell VR8205 Gas Valve −− Turn knob on gas
valve clockwise
ure 20.
7 − Wait five (5) minutes to clear out any gas. If you then
smell gas, STOP! Immediately call your gas supplier
from a neighbor's phone. Follow the gas supplier's in-
structions. If you do not smell gas go to next step.
8 − White Rodgers 36E Gas Valve −− Switch gas valve lever
to ON.
Honeywell VR8205 Gas Valve −− Turn knob on gas
valve counterclockwise
9 − Replace access panel.
10− Turn on all electrical power to unit.
11− Set thermostat to desired setting.
12− If the appliance will not operate, follow the instructions
To Turn Off Gas To Unit" and call your service techni-
cian or gas supplier.
Turning Off Gas To Unit
1 − Set thermostat to lowest setting.
2 − Turn off all electrical power to unit if service is to be
performed.
3 − Remove access panel.
4 − Switch lever on White Rodgers gas valve to OFF; turn
knob on Honeywell valve clockwise
force.
5 − Replace lower access panel.
to OFF. Do not force. See fig-
to ON. Do not force.
to OFF. Do not
C−Safety or Emergency Shutdown
Turn off unit power. Close manual and main gas valves.
D−Extended Period Shutdown
Turn off thermostat or set to UNOCCUPIED" mode. Close
all gas valves (both internal and external to unit) to guaran-
tee no gas leak into combustion chamber. Turn off power
to unit. All access panels, covers and vent caps must be in
place and secured.
IV−HEATING SYSTEM SERVICE CHECKS
A−A.G.A./C.G.A. Certification
All units are A.G.A. and or C.G.A. design certified without
modifications. Refer to the 80MGF Operation and Installa-
tion Instruction Manual Information.
B−Gas Piping
Gas supply piping should not allow more than 0.5"W.C.
drop in pressure between gas meter and unit. Supply gas
pipe must not be smaller than unit gas connection.
Compounds used on gas piping threaded joints should be
resistant to action of liquefied petroleum gases.
C−Testing Gas Piping
In case emergency shutdown is required, turn off
the main shut-off valve and disconnect the main
power to unit. These controls should be properly
labeled by the installer.
When pressure testing gas lines, the gas valve must be
disconnected and isolated. Gas valves can be damaged if
subjected to more than 0.5psig (14" W.C.). See figure 22. If
the pressure is equal to or less than 0.5psig (14"W.C.), use
the manual shut−off valve before pressure testing to iso-
late furnace from gas supply.
GAS PIPING TEST PROCEDURE
MANUAL MAIN SHUT−OFF VALVE
WILL NOT HOLD TEST PRESSURE
IN EXCESS OF 0.5 PSIG (14"W.C.)
GAS VALVE
Page 20
IMPORTANT
CAP
FIELD PROVIDED
LINE PRESSURE TAP
FIGURE 22