35
1. Turn OFF gas to furnace at the manual gas shutoff valve external to the furnace.
2. Turn off all electrical power to the system.
3. Outlet pressure tap connections:
White-Rodgers 36J22 valve: Back outlet pressure test screw (inlet/outlet pressure tap) out one turn (counterclockwise, not
more than one turn).
4. Attach a hose and manometer to the outlet pressure tap (White-Rodgers valve).
5. Turn ON the gas supply.
6. Turn on power and close thermostat “R” and “W” contacts to provide a call for heat.
7. Measure the gas manifold pressure with burners firing. Adjust
manifold pressure using the
Manifold Gas Pressure
table shown
on this page.
8. Remove regulator cover screw from the outlet pressure regulator
adjust tower and turn screw clockwise to increase pressure or
counterclockwise to decrease pressure. Replace regulator cover
screw.
9. Turn off all electrical power and gas supply to the system.
10. Remove the manometer hose from the hose barb fitting or outlet pressure tap.
11. Replace outlet pressure tap: White-Rodgers 36J22 valve: Turn outlet pressure test screw in to seal pressure port (clockwise,
7 in-lb minimum).
12. Turn on electrical power and gas supply to the system.
13. Close thermostat contacts “R” and “W” to energize the valve.
Using a leak detection solution or soap suds, check for leaks at outlet or screw (White-Rodgers valve). Bubbles forming indicate a
leak. SHUT OFF GAS AND REPAIR ALL LEAKS IMMEDIATELY!
NOTE:
For gas to gas conversion, consult your dealer for appropriate conversion.
G
AS
I
NPUT
R
ATE
M
EASUREMENT
(N
ATURAL
G
AS
O
NLY
)
The actual gas input rate to the furnace must never be greater than that specified on the unit rating plate. To measure natural gas
input using the gas meter, use the following procedure.
1. Turn OFF the gas supply to all other gas-burning appliances except the furnace.
2. While the furnace is operating at high fire rate, time and record one complete revolution of the gas meter dial, measuring
the smallest quantity, usually the dial that indicates 1/2 cu. ft. per revolution. You will use this number to calculate the
quantity of gas in cubic ft. if the furnace would consume if it ran steadily for one hour (3600 seconds).
3. If the 1/2 cu. ft. dial was used, multiply your number x 2.
EXAMPLE: If it took 23 seconds to complete one revolution of the 1/2 ft. dial (23 x 2 = 46).
This tells us that at this rate, it would take 46 seconds to consume one cu. ft. of gas. 3600 / 46 = 78.
This tells us that in one hour, the furnace would consume 78 cu. ft. of gas.
The typical value range for 1 cu. ft. of natural gas is around 1000 BTU. Check with your gas utility, if possible. In this
example, the furnace is consuming 78,000 BTUH.
NOTE:
The final manifold pressure cannot vary by more than ± 0.3” w.c. for Natural and + 0.5” for LP from the specified
setting. Consult your local gas supplier if additional input rate adjustment is required.
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
.
