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INSTRUCTIONS FOR CONVERSION
Step 5:
Gas Pressure Checking and Setting Procedure
1. Preparation
(1) It is assumed that the inlet gas pressure coming into the unit is within the min. to max.
allowed, as per the Data Rating Plate, for gas type to be used. The gas inlet pressure can be
checked at the threaded hose fitting of the 3/4 inch inlet gas connection to the unit by:
• turning off the gas valve,
• removing the screw from the hose fitting,
• attaching a gas pressure manometer,
• opening the gas valve and checking the incoming gas pressure.
"Should the pressure be out of range, adjustments need to be made by the gas supplier prior
to any internal adjustments".
If inlet pressure is within range close gas valve, remove Gas Pressure Manometer, reinstall
screw with washer into the threaded hose fitting, and reopen gas valve.
(2) Make sure the appliance is not in operation. Then, remove the screw from the Manifold
pressure check inlet. (Do not mix the screw up with the front cover screws as they are the
same type threads)
(3) Connect the hose of the manometer to the pressure check fitting.
2. Adjusting Manifold pressure settings <Minimum pressure should be set before
setting the maximum pressure>
(1A) Make sure that "DIP Switch" No.1 is set to the position for the appropriate gas type.
(1B) Minimum Manifold gas pressure 0.4 inches w.c.
Maximum Manifold gas pressure 2.4 inches w.c.
Note: A small Phillips head screwdriver will be needed if gas pressures are out of
specification and need to be re-adjusted.
(2) After ignition and combustion is started, by opening the hot water supply valve, set "DIP
Switch" No. 5 to ON position to set the combustion at a minimum capacity level. By turning
the minimum gas adjusting control knob under the "DIP Switch", set the gas pressure for
the minimum capacity level. Set the "DIP Switch" No. 5 to OFF.
Summary of Contents for MWH-180
Page 60: ... 58 WIRING DIAGRAM ...
Page 61: ... 59 WIRING DIAGRAM ...
