18
3. INPUT=GAS HTG VALUE x 3600 / SEC. PER CUBIC FOOT
Example:
Natural gas with a heating value of 1000 BTU per cubic
foot and 34 seconds per cubic foot as determined by Step 2, then:
Input = 1000 x 3600 / 34 = 106,000 BTU per Hour.
NOTE:
BTU content of the gas should be obtained from the gas
supplier. This measured input must not be greater than
shown on the unit rating plate.
Adjust input rate by varying the adjustment of the gas pressure
regulator on the gas valve. All adjustments must be made with fur-
nace operating at high fire and at normal operating temperature. A
manometer should be connected to the gas valve to verify pressure
is within the specified range (see following figures for manometer
connections). Clockwise rotation of the pressure regulator screw
increases pressure and gas flow rate. Turn screw counterclock-
wise to decrease pressure and gas flow rate. After adjustment the
furnace temperature rise must be within the range specified on
the unit data plate.
NOTE:
Thermal efficiency of the furnace is a
product efficiency rating determined under continuous operating
conditions independent of any installed system.
Pressure Regulator
Adjustment
(Under Cap Screw)
Gas Valve
On/Off
Selector
Switch
INLET
OUTLET
Inlet Pressure
Tap
Outlet Pressure
Tap
WHITE-RODGERS 36G22 - SINGLE STAGE
Inlet
Pressure Boss
Low Fire
Regulator Adjust
Manometer
Manometer
Hose
High Fire Regulator
Adjust
Regulator
Vent
Outlet
Pressure Boss
Open to
Atmosphere
WHITE-RODGERS 36G54 (2-STAGE) CONNECTED TO MANOMETER
PRESSURE ADJUSTMENTS
TO CONNECT MANOMETER TO GAS VALVE:
1. Back outlet pressure test screw (inlet/outlet pressure boss)
out one turn (counterclockwise, not more than one turn).
2. Attach a hose and manometer to the outlet pressure boss
of the valve.
TO REMOVE MANOMETER FROM GAS VALVE:
1. Remove manometer hose from outlet pressure boss.
2. Turn outlet pressure test screw in to seal pressure port
(clockwise, 7 in-lb. minimum).
3. Turn on electrical power and gas supply to the system.
4. Turn on system power and energize valve.
5. Using a leak detection solution or soap suds, check for
leaks at pressure boss screw. Bubbles forming indicate a
leak. SHUT OFF GAS AND FIX ALL LEAKS IMMEDIATELY.
T
O
PREVENT
UNRELIABLE
OPERATION
OR
EQUIPMENT
DAMAGE
,
THE
GAS
MANIFOLD
PRESSURE
MUST
BE
AS
SPECIFIED
ON
THE
UNIT
RATING
PLATE
. O
NLY
MINOR
ADJUSTMENTS
SHOULD
BE
MADE
BY
ADJUSTING
THE
GAS
VALVE
PRESSURE
REGULATOR
.
CAUTION
6. Relight all other appliances turned off in step 1. Be sure all
pilot burners are operating.
Main Burner Flame Check
Flames should be stable, soft and blue (dust may cause orange tips
but they must not be yellow) and extending directly outward from
the burner without curling, floating or lifting off.
Temperature Rise Check
Check the temperature rise through the unit by placing thermome-
ters in supply and return air registers as close to the unit as possible.
Thermometers must not be able to sample temperature directly
from the unit heat exchangers, or false readings could be obtained.
1. All registers must be open; all duct dampers must be in their
final (fully or partially open) position and the unit operated
for 15 minutes on HIGH FIRE before taking readings.
2. The temperature rise must be within the range specified
on the rating plate.
NOTE:
Air temperature rise is the temperature difference between
supply and return air.
With a properly designed system, the proper amount of tempera-
ture rise will normally be obtained when the unit is operated at
rated input with the recommended blower speed.
If the correct amount of temperature rise is not obtained, it may
be necessary to change the blower speed. A higher blower speed
will lower the temperature rise. A slower blower speed will increase
the temperature rise.
NOTE:
Blower speed MUST be set to give the correct air temperature
rise through the unit as marked on the rating plate.
NORMAL SEQUENCE OF OPERATION - HEATING
This unit has one (RS) Manual Reset Limit Control Switch. Check
the limit to make sure it has not tripped. The limit may arrive at
the job site tripped as a result of shipping shock.
If the vent motor comes on, but the unit does not attempt igni-
tion, check if the ALS (Automatic Reset High Limit Control Switch)
requires resetting.
1. With electricity and gas turned on, the system switch
