Gas Pressure Specifications
Type of | Inches WC | Regulator | |
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Gas | Min. | Max.* | Setting |
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Natural | 7.0 | 10.5 | 4.0 |
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Propane | 12.0 | 13.0 | 11.0 |
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*Do not exceed maximum inlet gas pressure. The minimum value shown is for input adjustment.
Table H: Gas Pressure Specifications
Gas Pressure Regulator
The gas valve is provided with pressure taps to meas- ure gas pressure upstream of the gas valve and downstream which is the same as the manifold pres- sure.
The gas pressure regulator is preset and sealed at 4 in. WC for natural gas, and 11 in. WC for propane gas. Between the gas valve and the burners is a 1/8 in. pipe plug. The pressure at this point, taken with a manome- ter, should be about 3.7 in. WC natural gas and 10.5 in. WC propane gas. Lo NOx models should be 3.9 in. WC natural gas only. If an adjustment is needed, remove seal and turn adjustment screw clockwise to increase pressure or
Water Connections & System Piping
The pipe size and fittings between the heater and the tank should be at least
Fig. 13: Heater with Storage Tank
14