B.
Pre-Adjust 2-Stage Gas Valve
NOTE:
The following furnaces with Fig. 6D type valves, DO NOT need to have the regulator spring replaced in the gas valve, but the valve
MUST be pre-adjusted for propane applications. The following furnaces with Fig. 6C type valves must have both springs replaced and the valve
MUST be pre-adjusted:
CAUTION: UNIT DAMAGE HAZARD
Failure to follow this caution may result in excess underfire and flashback.
The gas valve must be pre-adjusted before operating on propane gas. If left this way sooting and corrosion will occur leading to early
heat exchanger failure.
FOR FIG. 6C
1. Be sure gas and electrical supplies to furnace are off.
2. Remove caps that conceal adjustment screws for high- and low-heat stage gas-valve regulators. (See Fig. 6C.)
3. Turn low-heat stage adjusting screw clockwise (in) 9.5 turns. This will increase the manifold pressure closer to the propane low-heat set
point.
4. Turn high-heat stage adjusting screw clockwise (in) 13.5 turns. This will increase the manifold pressure closer to the propane high-heat
set point. Replace caps that conceal gas-valve regulator adjustment screws. Go to Procedure 3.
FOR FIG. 6D
1. Be sure gas and electrical supplies to furnace are off.
2. Remove caps that conceal adjustment screws for high- and low-heat stage gas-valve regulators. (See Fig. 6C.)
3. Turn low-heat stage adjusting screw (3/32-in. hex allen wrench) clockwise (in) 1 full turn. This will increase the manifold pressure closer
to the propane low-heat set point.
Fig. 5—NOx Device Location
A02195
REGULATOR SPRING
(PROPANE – WHITE, 6 TURNS
NATURAL – SILVER, 10 TURNS)
REGULATOR
ADJUSTMENT
SCREW
REGULATOR
SEAL CAP
GAS PRESSURE
REGULATOR
ADJUSTMENT
INLET
PRESSURE TAP
ON AND
OFF SWITCH
MANIFOLD
PRESSURE TAP
A01073
Fig. 6A—Single-Stage Gas Valve
REGULATOR
SEAL CAP
REGULATOR
ADJUSTMENT
SCREW
REGULATOR SPRING
(PROPANE - WHITE, 8.5 TURNS
NATURAL - SILVER, 8.5 TURNS)
GAS PRESSURE
REGULATOR
ADJUSTMENT
MANIFOLD
PRESSURE TAP
INLET
PRESSURE TAP
ON/OFF SWITCH
A04112
→
Fig. 6B—Single-Stage Gas Valve
58CTA
312AAV
58CVA
315AAV
58CTX
312JAV
58CVX
315JAV
—6—
→
→
