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this appliance is maintained. Proper maintenance is criti-
cal for your safety and the satisfactory operation of the
product.
Lennox strongly recommends annual in-
spection and maintenance of this appliance.
Contact
your Lennox dealer for an inspection by a licensed profes-
sional service technician (or equivalent).
DANGER
Danger of explosion.
There are circumstances in which odorant used with
LP/propane gas can lose its scent. In case of a leak,
LP/propane gas will settle close to the floor and may
be difficult to smell. An LP/propane leak detector
should be installed in all LP applications.
Do not attempt to bleed the gas lines of air. Call your
local gas provider.
Start−Up & Operation Information
WARNING
If you do not follow these instructions exactly, a fire
or explosion may result causing property damage,
personal injury or death.
BEFORE PLACING THE UNIT INTO OPERATION,
smell
all around the appliance area for gas. Be sure to smell next
to the floor because some gas is heavier than air and will
settle on the floor.
The gas valve on the ML180UHE will be equipped with a
gas control switch. Use only your hand to move the
switch. Never use tools. If the switch will not move by
hand, do not try to repair it. Call a licensed professional
service technician (or equivalent). Force or attempted re-
pair may result in a fire or explosion.
Placing the ML180UHE furnace into operation:
ML180UHE units are equipped with an ignition system.
Do not attempt to manually light burners on this furnace.
Each time the thermostat calls for heat, the burners will
automatically light. The ignitor does not get hot when
there is no call for heat on units with this ignition system.
Operating the Gas Valve (Figure 2)
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 switch on gas valve to
OFF
. See figure 2.
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 switch on gas valve to
ON
. See figure 2.
FIGURE 2
GAS VALVE SHOWN IN ON POSITION
MANIFOLD
PRESSURE
OUTLET
PORT
INLET
PRESSURE
PORT
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
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 section
Turning Off Gas to the Unit" and call your licensed
professional service technician (or equivalent).
Turning Off Gas to the 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 switch on gas valve
OFF
.
5 − Replace the upper access panel.
