W415-1117 / A / 03.11.14
44
IOM
IOM
17.2 TO SHUT DOWN THE FURNACE
17.0 INITIAL STARTUP PROCEDURES
17.1 TO START THE FURNACE
H21.0
This furnace is equipped with a HSI (Hot Surface Ignition) device. Each time that the room thermostat calls for
heat, the HSI lights the main burners directly. See the lighting instructions on the furnace.
When the gas supply is initially connected to the furnace, the gas piping may be full of air. In order to purge this
air, it is recommended that the ground union be loosened until the odor of gas is detected. When gas is detected,
immediately retighten the union and check for leaks. Allow
fi
ve minutes for any gas to dissipate before continu-
ing with the start-up procedure. Be sure proper ventilation is available to dilute and carry away any vented gas.
During initial start-up, it is not unusual for odor to come out of any room register. To ensure proper ventilation, it
is recommended to open windows and doors, before initial
fi
ring.
The furnace has a negative pressure switch that is a safety during a call for heat. The induced draft blower must
pull a negative pressure on the heat exchanger to close the negative pressure switch. The induce draft blower
must maintain at least the negative pressure switch set point for the furnace to operate. If the induced draft
blower fails to close or maintain the closing of the negative pressure switch, a “no heat call” would result.
NOTE
It is recommended that the drain trap assembly be primed before the initial startup. Refer to the instructions
on how to prime the condensate trap on the drain piping section in this manual. A dry trap will allow
fl
ue
gases to
fl
ow through the recovery coil drain, which will prevent the condensate from draining from the
recovery coil. If enough condensate accumulates in the recovery coil, the recovery coil pressure switch will
sense this condition and break its electrical contacts, and extinguish combustion. If this takes place, the
induced blower will stop after a brief post-purge cycle, the condensate will drain out and
fi
ll the trap. If the
thermostat is still calling for heat, the ignition sequence will start again after a 5 minute wait.
H21.1
1. Shut off the electrical power to the furnace and set the room thermostat to its lowest setting.
2. Remove the burner compartment access door.
IMPORTANT
:
ENSURE THAT THE MANUAL GAS VALVE SWITCH HAS BEEN IN THE “OFF” POSITION
FOR AT LEAST 5 MINUTES. DO NOT ATTEMPT TO MANUALLY LIGHT THE MAIN
BURNERS.
3. Turn the gas valve switch to the “ON” position.
4. Replace the burner compartment access door.
5. Turn on furnace appliance shut off valve.
6. Restore electrical power to the furnace.
7. Set the room thermostat to a point above room temperature to light the furnace.
8. After the burners are lit, set the room thermostat to the desired temperature.
H21.2
1. Set the room thermostat to below set point.
2. Remove the burner compartment access door.
3. Turn the gas valve switch to the “OFF” position.
4. The furnace appliance shut-off valve may be closed if desired.
5. Power to the furnace must remain on for the air conditioner to work.
