20
6. Disconnect the two wires leading to gas
control valve.
7. Remove three (3) bolts from U-shaped
manifold plate and orifice assembly.
8. Remove the main orifice and replace it with
the appropriate LP fuel orifice. Refer to the
rating plate on the furnace to determine the
firing rate for your application. If the firing
rate of your furnace has been converted,
ensure that the appropriate LP orifice for
the new firing rate is installed. Then, use
Table 4 to determine the proper LP orifice
for your firing rate.
9. Remove the regulator converter and its
black cover located on top of the gas valve
and invert. (See Figure 16 — For LP, the
red ring will be located at the bottom and the
“LP” stamping on the converter will appear
right side up.)
10. Screw converter back into the regulator,
hand tight plus
1/8 turn, and replace the black cover onto
the converter top to protect the threads.
11. Reinstall the burner assembly into the
furnace.
12. Reconnect the gas piping and electrical
wires to the gas valve.
Figure 17. Oil Pumps
AIR BLEED
VALVE
NOZZLE
PORT
NOZZLE
PORT
WEBSTER
SUNTEC
INLET PORT
INLET PORT
INLET PORT
AIR BLEED
VALVE
13. Open the manual shut-off valve and follow
the “Operating Instructions” as outlined
previously in this manual to put the furnace
into operation.
Adjusting the Burner
The air shutter is factory pre-set for installation
in a given furnace, as shown in Table 5. You
should not need to adjust the air shutter setting
of the gas gun burner except when converting
the firing rate of the furnace. For your installation,
check to ensure that the air shutter setting is
correct. It is very important that the combustion
air supply be ample without decreasing the
efficiency of the burner. An inadequate amount
of air can cause carbon monoxide (CO)
production. The carbon dioxide (CO2) content
of the flue products should be in the range of
8.0% to 9.0% for natural gas and 9.0% to 10.0%
for LP gas. The burner should run quietly.
For high altitude operation (altitudes greater
than 2,000 feet), the input should be de-rated by
4% for each 1,000 feet above sea level by
reducing the orifice size or decreasing the
manifold pressure. When decreasing the
manifold pressure, the pressure must not be
set below 3.2 in WC. If the pressure needs to
be set below 3.2 in WC to achieve the proper de-
rate, then change the orifice size and raise the
manifold pressure back to 3.5 in WC.
Figure 18. PO Oil Burner Electrode Settings
5/32" Gap
Electrode
5/16" ABOVE CL
Nozzle
1/16"
1-1/8" - 65,000 and 75,000
BTU/HR Inputs, FO Head
1-13/32" - 90,000 BTU/HR
Input, F3H Head
Summary of Contents for CMF 100-PG
Page 27: ......
