STA-RITE MAX-E-THERM SR400LP Instructions D'installation page 3

NOTICE:
The gas piping and
unions have been omitted for
clarity; make this test with all
gas piping connected (as for
normal service).
To Air Flow
Switch
Figure 1: Vent valve tap connection to mixer inlet
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 (Propane to NG)
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).
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Figure 2: Separate Jacket Halves
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).
Connection for
Test
To High Side
of Differential
Pressure Gauge
Vent
Press
Tap
To Low Side of
Figure 3: Swing Gas Line Out of the Way.
Differential
Pressure Gauge
6. Remove the gas orifice and O-Ring contained in the
union nearest the combination gas control valve.
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7. Install the O-Ring on the Natural Gas conversion ori-
fice. Verify the correct size of the Natural Gas orifice
included in your kit (see Table 2).
Table 2: Replacement N.G. Orifice Size Code
Model
SR400
SR333
SR200
8. Insert the Natural Gas orifice squarely in the gas line
union next to the combination gas valve (see Figure 4).
Figure 4: Install Orifice; Reconnect Unions.
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
Swing Gas Line
to One Side
Air Inlet
Tube
Part No. ID Stamp
42001-0311
42001-0321
42001-0331
Install O-Ring
Reconnect
Gas Line
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Remove
Orifice
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Size ('')
A .480
B .402
C .295
Install
Orifice