Adjusting Gas Pressure At The Water Heater; Part 8 - Water Piping; General Plumbing Connection Guidelines; Install A Backflow Preventer - Westinghouse WGRTNG199 Nstallation & Maintenance Manual

C. ADJUSTING GAS PRESSURE AT THE WATER HEATER
NOTE: Refer Figure 15 when adjusting gas pressure. Loosen the bolts before
checking the gas inlet pressure.
1. The water heater and its individual shutoff valve must be disconnected from the
gas supply piping system during any pressure testing of the system at test pressures
greater than ½ psi (3.5 kPa).
2. The water heater 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).
The minimum and maximum inlet gas line pressures must meet the requirements
shown in Table 15.
LP GAS
Minimum Pressure
Maximum Pressure
Table 15 – Gas Pressure Requirements
Do not fire (operate) the water heater until all connections have been completed and the heat exchanger is filled with water. Doing so
will damage the water heater and void the warranty.
PART 8 – WATER PIPING
A. GENERAL PLUMBING CONNECTION GUIDELINES

Pipe material must be suitable to meet local codes and industry standards.

The pipe must be cleaned and without blemish before any connections are made.

Do not apply a torch within 12" of the bottom connections of the water heater. Doing so could damage the water heater. Such
damages ARE NOT covered by product warranty.

The size of the hot water pipe should be ¾" diameter.

Isolation (shutoff valves) should be used to ease future servicing.

All piping should be insulated.
B. INSTALL A BACKFLOW PREVENTER
It may be recommended to use a back flow preventer – check local codes. If a back flow preventer or a no return valve is used, a
thermal expansion tank must be installed on the cold water supply between the water heater and valve.
To control thermal expansion, a thermal expansion tank should be installed in systems with an installed backflow preventer. DO NOT
use a closed type expansion tank. Follow expansion tank manufacturer's specifications to properly size an expansion tank to the
installation. Failure to properly accommodate thermal expansion could result in property damage, severe personal injury, or death.
C. PIPING THE WATER HEATER
Use at least the MINIMUM pipe size for all water heater loop piping This is to avoid the possibility of inadequate flow through the water
heater. Using less than the required minimum pipe size and piping could result in system problems, property damage, and premature
water heater failure. Such problems ARE NOT covered by product warranty.
Use both thread tape and pipe dope to connect to the ¾" domestic water inlet and outlet. Tankless isolation valves between the city
water supply and tank inlet are recommended for ease of service.
NATURAL GAS
3.5" WC
Minimum Pressure
14" WC
Maximum Pressure
3.5" WC
14" WC
NOTICE
Figure 15 – Inlet Gas Pressure Port Detail
WHL-004 REV. 12.17.14
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