10
f.
It is not necessary to convert the pilot orifice.
g.
For Honeywell gas valves with the regulator converter
(Figure 8), check for the letters NAT or LP on the pressure
regulator cap. Unscrew the cap, invert it, replace, and
tighten until snug.
h.
For the Robertshaw gas valve with the regulator con-
verter (Figure 9), remove the black cover and unscrew
the converter located on top of the gas valve. Invert the
converter. (For “LP” the red ring will be located at the
bottom and the “LP” stamping on the converter will appear
right side up.) Then screw converter back into the regu-
lator, hand tight plus 1/8 turn, and replace the black cover
onto the converter top to protect the threads.
i.
Reassemble the burner assembly into the furnace.
j.
Reconnect the gas piping and electrical wires to the gas
valve.
k.
Open the manual shut-off valve and follow the FURNACE
START-UP procedure as outlined previously in this manual
to put the furnace into operation.
NOTE: The pilot flame is adjustable by turning the adjustment
screw located on the gas valve with a small screwdriver. (See
Figure 10)
5. GAS SUPPLY, CONVERSION, AND
LIGHTING – M1G AND M1M MODELS
GAS PIPING
Sizing and installation of fuel lines must be in accordance with
federal, state and local regulations. All piping shall be black
iron pipe, or equivalently sized steel tubing. Internally tinned
copper tubing may be used for gas supply systems.
Fuel line installations other than typical installations shown in
Figure 7 must comply with the fuel piping provisions stated in
the Federal Manufactured Home Standard (H.U.D. TITLE 24,
PART 280) and the National Fuel Gas Code (ANSI-Z223.1/
NFPA-54).
a.
Optional fuel inlet lines are available for all gas furnace
models to permit the addition of a 1/2" F.P.T. shut-off
valve above the floor.
NOTE: Shut-off valve must be designed and listed for use
with liquid petroleum (LP gas).
The gas supply to your home will either be Natural Gas or LP
(bottle gas). Your furnace is factory equipped to operate on
Natural Gas. If your gas supply is LP, you must convert the
furnace. The necessary instructions for the gas conversion are
found on the lighting instruction label attached to the furnace in
Section 16, Service Guide.
For natural gas operation, the furnace is designed for 7" W.C.
inlet pressure. Pressure is reduced to 3-1/2" W.C. by the
pressure regulator in the gas valve. The maximum inlet
pressure for the valve is 13” W.C.
For L.P. gas, pressure to the gas valve must be more than 11"
W.C. but not more than 13" W.C. Pressure is reduced to 10"
W.C. by the pressure regulator in the gas valve.
GAS CONVERSION
This gas fired heating appliance was shipped from the factory
for use with natural gas. However, the appliance can be
converted for use with LP gas. Use the following procedure
for gas conversion of the burner.
ATMOSPHERIC AND DIRECT IGNITION FURNACES
a.
Follow the instructions to “Turn Off Gas to the Appliance.”
b.
Disconnect the gas pipe union and the electrical wires
connected to the gas valve.
c.
Remove the pilot tube and thermocouple from the gas
valve (M1G* only).
d.
To remove the gas valve assembly, remove screw(s)
from gas valve bracket. Gas valve and spud may be
removed. Orifice is located at the end of the spud
(M1G*,M1M*).
e.
Replace the main orifice with the L.P. gas orifice supplied
in the envelope located by the gas valve. Check to insure
the orifice size matches the nameplate. NOTE: For eleva-
tions over 2,000 feet, use Table 7 to determine orifice size.
To Gas
Supply
Floor
Control
Panel
On-Off-Fan
Switch
,,,
,,,
,,,
,,,
Alt. Fuel
Line Entry
Floor Cavity
Figure 7. Typical Gas Piping
CAUTION:
The furnace must be converted by a qualified
technician. Improper conversion can cause
unsafe operation, explosion, fire and/or
asphyxiation.
!
