Gas Piping & Connections - Bosch 830 ES Manual

26 | Installation instructions
4.9 Gas piping & connections
Before connecting the gas supply, check the rating plate on the right side
of the heater to be sure that the heater is rated for the same gas to which
it will be connected.
In the United States: The installation must conform with local codes or,
in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/
NFPA 54.
In Canada: The Installation must conform to CGA B149 INSTALLATION
CODES and/or local installation codes.
DANGER: Explosion hazard!
▶ DO NOT connect to an unregulated or high pressure
propane line or to a high pressure commercial natural
gas line.
DANGER: Explosion hazard!
▶ The heater must be isolated from the gas supply
piping system during any pressure testing of that
system at test pressures equal to or more than 0.5
psig. If overpressure has occurred, such as through
improper testing of the gas lines or malfunction of the
supply system, the gas valve must be checked for safe
operation.
GAS CONNECTIONS
▶ Install a manual gas shut off valve on the gas supply line within easy
reach of the appliance.
▶ Install a union when connecting gas supply.
▶ The minimum internal diameter required for any appliance connector
is ¾ ", see chapter 4.9.1 for more details on pipe sizing.
▶ Undersized flexible appliance connector not permitted.
▶ National Fuel Gas Code requires that a sediment trap (drip leg) be
installed on gas appliances not so equipped. The drip leg must be
accessible and not subject to freezing conditions. Install in
accordance with the recommendations of the serving gas supplier,
see fig. 2.
Fig. 33 Gas connection
[1] Gas supply
[2] Cap
[LA] Minimum 3"
Once connections are made, check for gas leaks at all joints. Apply some
gas leak detection solution to all gas fittings. Bubbles are a sign of a leak.
A combustible gas detector may also be used to detect for leaks.
DANGER: Explosion hazard!
▶ If you detect a leak, shut off the gas. Tighten
appropriate fittings to stop leak. Turn the gas on and
check again with a gas leak detection solution. Never
test for gas leaks using a match or flame.
6 720 644 936 (2013/01)
GAS LINE SIZING
The gas supply piping for a single heater should be sized for a maximum
draw of 175,000 BTU/hr. Measure the length of gas supply line from the
building's gas main to the heater and use the chapter 4.9.1 and 4.9.2,
page 27 or the gas line manufacturer's sizing tables to determine the
pipe diameter necessary. If there are more gas drawing appliances on
the line, size the gas line according to the total maximum amount of BTU
draw input rating of for all appliances combined.
Note: Undersizing the gas line may result in diminished hot water flow
rate and temperature. See chapter 4.14, page 31 for the procedure to
measure gas pressure. Proper gas pressure must be confirmed at time of
installation.
830 ES