CAUTION
The water heater and individual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of the system at test pressures in excess of ½ psi (3.5 kPa). The water heater must be isolated from the gas supply piping system by closing its manual shutoff valve during any pressure testing of the gas supply system at test pressures equal to or less than ½ psi (3.5 kPa). The supply line must be capped when not connected to the water heater.
If copper supply lines are used, they must be internally tinned and certified for gas service.
Figure 24. Drip Leg
The gas supply lines must meet all requirements of the National Fuel Gas Code ANSI Z223.1 (Latest Edition), or in Canada CAN/CGA B149.1 Natural Gas Installation Code (Latest Edition) or CAN/CGA B149.2 Propane Installation Code (Latest Edition).
GAS METER SIZE – NATURAL GASES ONLY
Be sure that the gas meter has sufficient capacity to supply the full rated gas input of the water heater as well as the requirements of all other gas fired equipment supplied by the meter. If the gas meter is too small, ask the gas company to install a larger meter having adequate capacity.
GAS PRESSURE REGULATION
Main line gas pressure to the water heater should be between a maximum 14 inches (3483.8 Pa) W.C. and a minimum supply pressure as shown on the rating plate. The inlet gas pressure must not exceed the maximum value. In some installations, a regulator sized for the input rating of the water heater will need to be installed just ahead of the inlet gas connection to the water heater to reduce excess gas pressure or surges in gas pressure.
BEFORE PLACING THE WATER HEATER IN OPERATION, CHECK FOR GAS LEAKAGE. USE SOAP AND WATER SOLUTION OR OTHER MATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCATING GAS LEAKS.
WARNING
DO NOT USE MATCHES, CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.
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