Page 18
Unit Start-Up
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING
Do not use this furnace if any part has been underĆ
water. Immediately call a qualified service techniĆ
cian to inspect the furnace and to replace any part
of the control system and any gas control which
has been under water.
WARNING
If overheating occurs or if gas supply fails to shut
off, shut off the manual gas valve to the appliance
before shutting off electrical supply.
CAUTION
Before attempting to perform any service or mainteĆ
nance, turn the electrical power to unit OFF at isolaĆ
tor switch.
BEFORE LIGHTING
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.
Use only your hand to turn the main manual gas cock. Never
use tools. If the knob will not turn by hand, do not try to repair
it, call a qualified service technician. Force or attempted reĆ
pair may result in a fire or explosion.
PLACING FURNACE INTO OPERATION
G24MCE units are equipped with an automatic direct
spark ignition system. Do not attempt to manually light
burners on these Furnaces. Each time the thermostat
calls for heat, the burners will automatically light.
WARNING
If you do not follow these instructions exactly, a fire
or explosion may result causing property damage,
personal injury or death.
GAS VALVE OPERATION (Figure 23)
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 - 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
instructions. If you do not smell gas go to next step.
S.I.T. GAS VALVE
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
MANIFOLD
PRESSURE
OUTLET
FIGURE 23
6- Turn on all electrical power to the unit.
7- Set the thermostat to desired setting.
8- If the appliance will not operate, follow the instrucĆ
tions Turning Off Gas To Unit" and call your service
technician or gas supplier.
NOTE-When unit is initially started, steps 1 through 7
may need to be repeated to purge air from gas line.
TURNING OFF GAS TO UNIT
1 - Set the thermostat to lowest setting.
2 - Turn off all electrical power to the unit if service is to
be performed.
Heating Sequence of Operation
1 - When thermostat calls for heat, combustion air blowĆ
er starts after a 5 second delay.
2 - Combustion air pressure switch proves blower opĆ
eration, then allows power to ignition control. Switch
is factory set and requires no adjustment.
3 - After 15-second prepurge, spark ignitor energizes
and gas valve solenoid valves open.
4 - Spark ignites gas, ignition sensor proves the flame
and combustion process continues.
5 - If flame is not detected after first ignition trial, igniĆ
tion control will repeat steps 3 and 4 four more
times before locking out. To reĆestablish ignition
attempts after lockout, proceed as follows:
a - Turn
OFF
the power to the furnace.
b - Move the thermostat control from the HEAT" to
the OFF" position.
c - Turn
ON
the power to the furnace.
d - Move the thermostat control from the OFF" to
HEAT" position.
