GMES96-U Installation Manual
27
AIR FLOW
SIDE RETURN
EXTERNAL FILTER
RACK KIT
(EITHER SIDE)
Possible Upright Upflow
Figure 32
HORIZONTAL INSTALLATIONS
Filters must be installed in either the central return register or in
the return air duct work.
S
TARTUP
P
ROCEDURE
& A
DJUSTMENT
Furnace must have a 115 VAC power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation. In addition to the following start-up and adjustment
items, refer to further information in Operational Checks sec-
tion.
DRAIN TRAP PRIMING
The drain trap MUST be primed prior to furnace startup. To
prime, fill both sides of the drain trap with water. This ensures
proper furnace drainage upon startup and prohibits the possibil-
ity of flue gases escaping through the drain system.
FURNACE OPERATION
Purge gas lines of air prior to startup. Be sure not purge lines
into an enclosed burner compartment. Follow NFPA 54, National
Fuel Gas Code 8.1.
Check for leaks using an approved chloride-free soap and water
solution, an electronic combustible gas detector, or other ap-
proved method.
FURNACE STARTUP
1. Close the manual gas shutoff valve external to the furnace.
2. Turn off the electrical power to the furnace.
3. Set the room thermostat to the lowest possible setting.
4. Remove the burner compartment door.
NOTE: This furnace is equipped with an ignition device which
automatically lights the burner. Do not try to light the burner by
hand.
5. Move the furnace gas valve manual control to the OFF
position.
6. Wait five minutes then smell for gas. Be sure check
near the floor as some types of gas are heavier than
air.
7. If you smell gas after five minutes, immediately follow
the safety instructions in the Safety Considerations
on page 3 of this manual. If you do not smell gas
after five minutes, move the furnace gas valve
manual control to the ON position.
8. Replace the burner compartment door.
9. Open the manual gas shutoff valve external to the furnace.
10. Turn on the electrical power to the furnace.
11. Adjust the thermostat to a setting above room
temperature.
12. After the burners are lit, set the thermostat to desired
temperature.
FURNACE SHUTDOWN
1. Set the thermostat to the lowest setting.
The integrated control will close the gas valve and
extinguish flame. Following a 30 second delay, the induced
draft blower will be de-energized. The circulator blower
will shut down when the time delay expires (Time delay
is selectable on all models).
2. Remove the burner compartment door and move the
furnace gas valve manual control to the OFF position.
3. Close the manual gas shutoff valve external to the furnace.
4. Replace the burner compartment door.
GAS SUPPLY PRESSURE MEASUREMENT
GAS PRESSURE TEST
CAUTION
T
O
PREVENT
UNRELIABLE
OPERATION
OR
EQUIPMENT
DAMAGE
,
THE
INLET
GAS
SUPPLY
PRESSURE
MUST
BE
AS
SPECIFIED
ON
THE
UNIT
RATING
PLATE
WITH
ALL
OTHER
HOUSEHOLD
GAS
FIRED
APPLIANCES
OPERATING
.
The line pressure supplied to the gas valve must be within the
range specified on Table 5 on page 22. The supply pressure can
be measured at the gas valve inlet pressure tap or at a hose
fitting installed in the gas piping drip leg. The supply pressure
must be measured with the burners operating. To measure the
gas supply pressure, use the following procedure.
1. Turn OFF gas to furnace at the manual gas shutoff valve
external to the furnace. Back inlet pressure test port
screw turn counter clockwise, not more than one turn.
2. Connect a calibrated water U tube manometer (or
appropriate gas pressure gauge) at either the gas valve
inlet pressure tap or the gas piping drip leg. See White-
Rodgers 36J22Y-204 gas valve figure below for location
of inlet pressure tap.