NOTICE:
Before converting the heater, make the necessary
gas connections to the new gas supply, following the
instructions in the heater owner’s manual.
Verify the maximum and minimum regulated gas pressures
from the gas supply. These pressures must be within the
range listed on the conversion plate.
Conversion Procedure (NG to Propane)
1. Turn off the electrical supply to the heater; turn off the
pump; turn off the manual gas supply valve to the heater.
2. Unbolt and separate the top jacket halves (see Figure 2).
3. Unscrew completely the 3/4" gas line union closest to
the combination gas control valve.
4. Loosen the 3/4" gas line union directly above the air
inlet tube.
5. Loosen the pipe clamp holding the gas line to the
upper control support and swing the gas line loop out
of the way (see Figure 3).
6. Remove the gas orifice and O-Ring contained in the
union nearest the combination gas control valve.
7. Install the O-Ring on the Propane conversion orifice.
Verify the correct size of the Propane orifice included
in your kit (see Table 2).
Table 2: Replacement Propane Orifice Size Code
Model
Part No.
ID Stamp
Size (")
SR/SRC400
42001-0341
D
.409
SR/SRC333
42001-0351
E
.340
SR/SRC200
42001-0361
F
.244
8. Insert the Propane orifice squarely in the gas line union
next to the combination gas valve (see Figure 4).
9. Swing the gas loop and union half back into place
and tighten both unions securely.
10. Tighten the pipe clamp holding the gas line to the top
control support.
11. Use a 3/16" hex key to remove the plug from the
‘PRESSURE TAP’ port on the outlet side of the
Combination Gas Control Valve.
3
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To High Side
of Differential
Pressure Gauge
Connection for
Test
To Air Flow
Switch
To Low Side of
Differential
Pressure Gauge
Press
Tap
Vent
NOTICE:
The gas piping and
unions have been omitted for
clarity; make this test with all
gas piping connected (as for
normal service).
2585 0497
2801 0497
Remove
Orifice
Air Inlet
Tube
Swing Gas Line
to One Side
2.5X
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Install O-Ring
Install
Orifice
Reconnect
Gas Line
Figure 1: Vent valve tap connection to mixer inlet
Figure 4: Install Orifice; Reconnect Unions.
Figure 3: Swing Gas Line Out of the Way.
Figure 2: Separate Jacket Halves
