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Your furnace is a gas appliance.
It is critical that the gas
supplied to the unit be completely burned to avoid the pro-
duction of carbon monoxide gas. Complete combustion of
the gas requires, but is not limited to, correct gas pressure
and gas flow rate, adequate combustion, air, and proper
venting.
WARNING
Carbon monoxide gas is invisible, odorless and toxic.
Exposure to carbon monoxide gas can cause personal in-
jury and even death to all occupants, including pets. Any
item that is powered by or gives off heat from a combus-
tion process (including lawn mowers, automobiles, and
fireplaces) has the potential to produce carbon monoxide
gas. Because of this,
Lennox recommends the use of
a carbon monoxide detector in your home, even if
you do not own gas appliances.
Reliable detectors are
available at reasonable retail prices. Contact your Lennox
dealer for more details about this investment in your safe-
ty.
Your furnace is designed to meet standards set by nation-
al agencies, and to operate safely when properly installed
and maintained. However, the unit’s performance can be
greatly impacted by the individual installation and the op-
erating environment. It is your responsibility to ensure that
this appliance is maintained. Proper maintenance is crit-
ical for your safety and the satisfactory operation of the
product.
Lennox strongly recommends annual inspec-
tion and maintenance of this appliance.
Contact your
Lennox dealer for an inspection by a licensed professional
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 ML195UHF 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 repair may result in a fire or
explosion.
Placing the ML195UH furnace into operation:
ML195UH 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 auto-
matically 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
instructions. If you do not smell gas go to next step.
8 - Move switch on gas valve to ON. See figure 2.
GAS VALVE SHOWN IN ON POSITION
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
MANIFOLD
PRESSURE
OUTLET
FIGURE 2
9 - Replace the upper access panel.
10 - Turn on all electrical power 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.
