Gas Piping; Gas Piping Guidelines; Gas Supply Line Pressures - Navien NR-180 Installation Manual

Gas Water Heater Installation

█ Gas Piping:

 Navien recommends the Water Heater be the first appliance installed
downstream of the gas meter to ensure it will have sufficient gas supply.
 Use the charts on the following pages to properly size the gas supply line.
 The gas connection fitting on all Navien units is ¾". DO NOT use less than ¾" piping.
 When using flexible gas line, ensure the pipe's inner diameter is sufficient to supply
the required BTUs, also ensure that the flexible line has no crimps or tight bends this
will restrict gas flow.
 Install a manual gas shut-off valve on the gas supply line and the water heater.
 When using rigid pipe, Navien recommends the installation of a union on the gas
supply pipe close to the water heater to facilitate any future maintenance and
service.

Gas supply Line Pressures:

1. The minimum and maximum inlet gas pressures are:
Natural Gas Min. 5.0(6.0 : 180)" WC - Max. 10.5" WC
Propane Gas Min. 8.0(9.0 : 180)" WC - Max. 13.5" WC
2. Gas pressures over and above the specified ranges will result in adverse
performance and dangerous operating conditions, any damage resulting from
extreme gas supply pressures will not be covered by the limited warranty.
3. Until pressure testing of the main gas supply line is completed, ensure the gas line to
the Navien Water Heater is disconnected to avoid any damage to the Water Heater.
4. The appliance must be isolated from the gas supply piping system by closing its
individual manual shutoff valve during any pressure testing of the gas supply piping
system at test pressures equal to or less than ½ psi (3.5 kPa);
5. The gas appliance and its gas connections must be leak tested before placing the
appliance in operation. Leaks can be found by using a gas leak detetion device or
by applying soapy water to all gas fittings. Should bubbles occur tighten those
connections and re-test.
6. Always purge the gas line for any debris before connecting to the Water Heater gas
inlet.
7. Never use an open flame to test for gas leaks, as property damage, personal injury,
or death could result.
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