Navien CH-180 Installation Manual page 33

Measuring Inlet Gas Pressure:
4. Connect a manometer to the pressure port and reset it to
zero.
5. Re-open the manual gas valve. Check to see that there are
no gas leaks.
6. Open multiple fixtures that have high flow rates ( i.e. bathtub, showers, kitchen sink)
to ramp the Water Heater / Heating Boiler up to its maximum burn.
7. When the Navien Water Heater / Heating Boiler is at maximum burn, check the
inlet gas pressure reading on the manometer, it should read between 3.75"and
10.5"WC for Natural Gas / 10.5" and 13.5"WC for Propane gas.
8. The maximum inlet gas pressure must not exceed the value specified by the
manufacturer and that the minimum value listed is for the purposes of input
adjustment.
9. The Water Heater / Heating Boiler and individual shutoff valve must be
disconnected from the gas supply piping system during any pressure testing
of that system at test pressures in excess of 1/2 psi (3.5 kPa).
10. The Water Heater / Heating Boiler must be isolated from the gas supply
system by closing its individual manual shutoff valve during any pressure
testing of the gas supply piping system at test pressrues equal to or less
than 1/2 psi (3.5 kPa).
Pressure test port on gas line
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