Page 15
1 -
STOP
! Read the safety information at the beginning of
this section.
2 - Set the thermostat to the lowest setting.
3 - Turn off all electrical power to the unit.
4 - This furnace is equipped with an ignition device which
automatically lights the burners. Do
not
try to light the
burners by hand.
5 - Remove the upper access panel.
6 - Move gas valve lever to
OFF position
. Do not force.
See figure 12.
7 - Wait five 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 instruc
tions. If you do not smell gas go to next step.
8 - Move gas valve lever to
ON position
. Do not force.
See figure 12.
9 - Replace the upper access panel.
10- Turn on all electrical power to to the unit.
11- Set the thermostat to desired setting.
NOTE - When unit is initially started, steps 1 through 11
may need to be repeated to purge air from gas line.
12- If the appliance will not operate, follow the instructions
“Turning Off Gas to Unit” and call the gas supplier.
Turning Off Gas to Unit
1 - Set the thermostat to the lowest setting.
2 - Turn off all electrical power to the unit if service is to be
performed.
3 - Remove the upper access panel.
4 - Move gas valve lever to
OFF position
. Do not force.
See figure 12.
5 - Replace the upper access panel.
B- Safety or Emergency Shutdown
Disconnect main power to unit. Close manual and main gas
valves.
C- 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 and covers must be in place and se
cured.
IV-HEATING SYSTEM SERVICE CHECKS
A- Certification
All units are Australian Gas Installation Code (AS/
NZS5601) certified. Refer to the ML180UHA Installation In
struction.
B- Gas Piping
Gas supply piping should not allow more than 125Pa (13
mm W.C.)drop in pressure between gas meter and unit.
Supply gas pipe must not be smaller than unit gas connec
tion.
Compounds used on gas piping threaded joints should be
resistant to action of liquefied petroleum gases.
C- Testing Gas Piping
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 outside
the furnace cabinet.
IMPORTANT
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.
WARNING
Do not exceed 68Nm (50 ft-lbs) torque when attach
ing the gas piping to the gas valve.
When pressure testing gas lines, the gas valve must be dis
connected and isolated. Gas valves can be damaged if
subjected to more than 3.48kPag (0.5psig) See figure 13
.
If
the pressure is equal to or less than 3.48kPag (0.5psig),
close the manual shut-off valve before pressure testing to
isolate furnace from gas supply.
FIGURE 13
MANUAL MAIN SHUT-OFF VALVE
WILL NOT HOLD TEST PRESSURE IN EXCESS
OF 3.48kPa (0.5 PSIG 355 mm W.C.)
GAS VALVE
CAP
GAS PIPING TEST PROCEDURE
FIELD PROVIDED
LINE PRESSURE TAP
When checking piping connections for gas leaks, use pre
ferred means. Kitchen detergents can cause harmful corro
sion on various metals used in gas piping. Use of a specialty
Gas Leak Detector is strongly recommended.
Do not use matches, candles, flame or any other source of
ignition to check for gas leaks.
