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Installation instructions
25
3.9
Water connections
B
When facing the heater, the ¾” cold connection is on
the bottom right and the hot connection is on the bot-
tom left. Centrally locating the water heater is recom-
mended to keep hot water distribution times even
throughout the structure.
Fig. 30
B
The use of unions when connecting both water
pipes to the inlet and outlet connections is
required. This will facilitate any necessary serv-
icing.
B
Plastic or PEX type plumbing line materials are not
suitable for connecting directly to the water heater.
B
Although water piping throughout the building may
be other than copper, we recommend that copper or
suitably rated stainless steel flex line piping be used
for the water connections for 1.5’ on either side of
the water heater (follow local codes if more
stringent).
B
Never sweat any piping directly to or beneath
the water connections, as damage can occur to
the internal water valve from heating of the
pipe.
B
Keep water inlet and outlet pipes to no less
than ¾" (19.05mm) diameter to allow the full
flow capacity.
B
If the cold and hot connections to the heater are
reversed, the heater will not function. Be certain there
are no loose particles or dirt in the piping. Blow out
or flush the lines before connecting to the water
heater.
B
Full port shutoff valves should be installed on both
the cold water supply and hot water outlet lines to
facilitate servicing the heater (see Fig. 31).
B
For installation on a private well system with the use
of a pressure tank, the lowest pressure range setting
recommended is 40-60 psi (2.75 and 4.15 bar).
3.10 Water quality
Water quality can have an impact on appliance
longevity and may not be covered under the
manufacturer's warranty.
For water analysis data call your local water department,
or if on a well, have well water analyzed periodically. If
water quality exceeds one or more of the values
specified below, Bosch recommends consulting a local
water treatment professional for water softening/
conditioning options.
Connecting the pressure relief valve (PRV)
A listed pressure relief valve supplied with the heater
must be installed at the time of installation.
No valve is
to be placed between the PRV and the heater.
No
reducing coupling or other restriction may be installed
in the discharge line. The discharge line must be a
minimum of 4” above a drain and installed such that it
allows complete drainage of both the PRV and the line.
The discharge line must be placed where it will not
cause any damage.
The location of the PRV must be readily accessible for
servicing or replacement, and be mounted as close to
Warning:
This heater is not approved
for preheated water applications.
See
chapter 3.11
for
approved
recirculating application.
Warning:
In
applications
where
inlet
water
temperature can exceed 140°F (60ºC), a
3-way valve or mixing valve must be
installed before the appliance to prevent
water exceeding 140°F (60°C) from
entering the appliance.
HOT
COLD
Description
Max. Levels
pH
pH
6.5 - 8.5
TDS (total Dissolved
Solids)
mg/l or ppm
500
Total hardness
mg/l or ppm
100
(6 grains)
Aluminum
mg/l or ppm
2.0
Chlorides
mg/l or ppm
250
Copper
mg/l or ppm
1.0
Iron
mg/l or ppm
0.3
Manganese
mg/l or ppm
0.05
Zinc
mg/l or ppm
5.0
Table 13
