GPG14M Installation Manual

14
Gas Supply And Manifold Check
Gas supply pressure and manifold pressure with the burners
operating must be as specified on the rating plate.
GAS SUPPLY PRESSURE MEASUREMENT
T O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE , THE
I
NLET GAS SUPPLY PRESSURE MUST BE AS SPECIFIED ON THE UNIT
RATING PLATE WITH ALL OTHER HOUSEHOLD GAS FIRED APPLIANCES
OPERATING .
CAUTION
The line pressure supplied to the gas valve must be within the
range specified in the Inlet Gas Supply Pressure table. 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 pres-
sure must be measured with the unit OFF. To measure inlet pres-
sure, use the following procedure.
Pressure Regulator
Adjustment
(Under Cap Screw)
Gas Valve
On/Off
Selector
Switch
INLET
OUTLET
Inlet Pressure
Tap
Outlet Pressure
Tap
White-Rodgers Model 36G22
Gas Valve On/Off
Selector Switch
Inlet
Pressure
Ta p
Pressure Regulator
(under cap screw)
Outlet
Pressure
Ta p
Honeywell Model VR8215 (Single-Stage)
Inlet
Pressure Boss
Low Fire
Regulator Adjust
High Fire Regulator
Adjust
Regulator
Vent
Outlet
Pressure Boss
White-Rodgers Model 36G54
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. Inlet pressure tap connections:
a. Honeywell VR8215 Valve:
Remove the inlet pressure boss plug. Install an 1/8” NPT
hose barb fitting into the outlet pressure tap.
b. White-Rodgers 36G22 or 36G54 valve:
Back inlet pressure test screw (inlet pressure boss) out
one turn (counterclockwise, not more than one turn).
4. Attach a hose and manometer to the outlet pressure barb
fitting (Honeywell valve) or inlet pressure boss (White-
Rodgers valve).
5. Turn ON the gas supply.
6. Turn On power and close thermostat “R” and “W” contacts,
or “R” and “W1” + “W2” for two-stage models, 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 supply pressure with burners firing. Adjust
supply pressure using the Inlet Gas Supply Pressure table
shown below. If supply pressure reading differs from the
table, make necessary adjustments to pressure regulator,
gas piping size, etc., and/or consult with local gas utility.
Propane Gas
Natural Gas
Inlet Gas Supply Pressure
Minimum:5.0" W.C. Maximum :10.0" W.C.
Minimum:11.0" W.C. Maximum :13.0" W.C.
9. Turn OFF all electrical power and gas supply to the system.
10.Remove the manometer hose from the hose barb fitting
or inlet pressure boss.
11. Replace inlet pressure tap:
a. Honeywell VR8215 valve:
Remove the 1/8” NPT hose barb fitting from the inlet
pressure tap. Replace the inlet pressure boss plug and
seal with a high quality thread sealer.
b. White-Rodgers 36G22 or 36G54 valve:
Turn inlet pressure test screw in to seal pressure port
(clockwise, 7 in-lb minimum).