Goodman MH8 Installation Instructions Manual page 28

S - P
TART UP ROCEDURE AND
Gas Line
Gas
Shutoff
Valve
Drip Leg Cap
With Fitting
Measuring Inlet Gas Pressure (Alt. Method)
G M P
AS ANIFOLD RESSURE
T
O PREVENT UNRELIABLE OPERATION
GAS MANIFOLD PRESSURE MUST
. O
PLATE NLY MINOR ADJUSTMENTS
THE GAS VALVE PRESSURE REGULATOR
HIGH VOLTAGE !
D
ISCONNECT ALL POWER BEFORE
. M
INSTALLING THIS UNIT ULTIPLE
. F
BE PRESENT AILURE TO DO
,
DAMAGE PERSONAL INJURY
M S S
ODELS USING INGLE
This valve is shipped from the factory with the regulator preset
(see control label).
Consult the appliance rating plate to ensure burner manifold
pressure is as specified. If another outlet pressure is required,
follow these steps.
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:
a. Honeywell VR8215 valve:
Remove the outlet pressure boss plug. Install an 1/8"
NPT hose barb fitting into the outlet pressure tap.
b. White-Rodgers 36G22 valve:
Back outlet pressure test screw (outlet pressure boss)
out one turn (counterclockwise, not more than one
turn).
A
DJUSTMENT
Gas Line
To Furnace
Manometer Hose
M A
EASUREMENT AND DJUSTMENT
CAUTION
OR EQUIPMENT DAMAGE
BE AS SPECIFIED ON THE UNIT
SHOULD BE MADE BY ADJUSTING
.
WARNING
SERVICING OR
POWER SOURCES MAY
SO MAY CAUSE PROPERTY
.
OR DEATH
G V
TAGE AS ALVES
4. Attach a hose and manometer to the outlet pressure
barb fitting (Honeywell valve) or outlet pressure boss
(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. Using a leak detection solution or soap suds, check for
leaks at outlet pressure boss plug (Honeywell valve) or
screw (White-Rodgers valve). Bubbles forming indicate
a leak. SHUT OFF GAS AND REPAIR ALL LEAKS
IMMEDIATELY!
8. Measure the gas manifold pressure with burners firing.
Adjust manifold pressure using the Manifold Gas
Pressure table shown below.
Propane Gas
9. Remove regulator cover screw from the outlet pressure
regulator and turn screw clockwise to increase pressure
or counterclockwise to decrease pressure. Replace
regulator cover screw.
10. Turn OFF all electrical power and gas supply to the
,
THE
system.
RATING
11. Remove the manometer hose from the hose barb fitting
or outlet pressure boss.
12. Replace outlet pressure tap:
a. Honeywell VR8215 valve:
Remove the 1/8" NPT hose barb fitting from the outlet
pressure tap. Replace the outlet pressure boss plug
and seal with a high quality thread sealer.
b. White-Rodgers 36G22 valve: Turn outlet pressure test
screw in to seal pressure port (clockwise, 7 in-lb
minimum).
13. Turn ON electrical power and gas supply to the system.
14. Close thermostat contacts to provide a call for heat.
15. Retest for leaks. If bubbles form, SHUT OFF GAS AND
REPAIR ALL LEAKS IMMEDIATELY!
M
ODELS USING
T
O PREVENT UNRELIABLE
GAS MANIFOLD
. O
PLATE NLY
THE GAS VALVE
Only small variations in gas pressure should be made by ad-
justing the gas valve pressure regulator. The manifold pressure
must be measured with the burners operating. To measure
and adjust the manifold pressure, use the following procedure.
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.
28
Manifold Gas Pressure
Natural Gas
T S G V
WO TAGE AS ALVES
CAUTION
OPERATION OR EQUIPMENT
PRESSURE MUST BE AS SPECIFIED
MINOR ADJUSTMENTS SHOULD
.
PRESSURE REGULATOR
3.5" w.c.
10.0" w.c.
,
DAMAGE THE
ON THE UNIT RATING
BE MADE BY ADJUSTING