Gas Piping & Connections - Bosch GWH 635 ES User Manual

Fig. 20 Vertical venting
Chimney (combustion air piping not being
shown)
A condensate drain tube must be attached to the
exhaust collar of the heater for all vent type applications,
see page, see page 11.
6 720 607 072
installation - Masonry
2.10
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 should conform with CGA
B149 INSTALLATION CODES and/or local installation
codes.
GAS LINE SIZING
The gas supply piping should be sized according to the
National Fuel Gas Code for a maximum draw of
175,000 BTUH. First determine the effective length of
the gas supply line by measuring the actual length of
piping, and then adding 5 ft. (1.52m) for every elbow or
"T" to the actual length. Use the charts in Fig. 22 to
determine the pipe
accommodate the BTU (Wh) demand of the unit. If
there are more gas drawing appliances on the line, size
according to the maximum amount of BTU (Wh)
demand.
Note: It is important that if any flexible gas line is used,
above or below ground between the gas supply meter/
regulator and the water heater, that it be sized properly.
Consult the gas sizing specification tables provided by
the flexible gas line manufacturer and sample CSST
flexible gas line tables in Figure 22.
Gas piping
Fig. 21
B Install a manual gas shut off valve, on the gas supply
line.
B The use of a union when connecting gas pipe to the
gas inlet connection is critical, this will facilitate any
necessary servicing and cleaning of the inlet gas
particle screen.
B Flexible gas line connectors are not recommended
because they are commonly undersized and restrict
gas flow. Oversize the diameter of any flexible gas
appliance connector if one must be used.
Appliance details
diameter necessary
Inlet gas particle screen
to
15