Water Piping - Bosch 660 EF User Manual

Installation instructions
3.9

Water piping

Installation and service must be performed by a quali-
fied plumber. In the Commonwealth of Massachusetts,
this product must be installed by a licensed plumber or
gas fitter in accordance with the Massachusetts Plumb-
ing and Fuel Gas Code 248 CMR Sections 2.00 and
5.00. Observe all applicable codes.
This appliance is suitable for potable water and space
heating applications. Do not use this appliance if any
part has been underwater. Immediately call a qualified
service technician to inspect the appliance and replace
any part of the control system and gas control which
has been under water. If the water heater is installed in
a closed water supply system, such as one having a
backflow preventer in the coldwater supply line, means
shall be provided to control thermal expansion. Contact
the water supplier or a local plumbing inspector on how
to control this situation. A pressure relief valve must be
installed near the hot water outlet that is rated in
accordance with and complying with either The Stand-
ard for Relief Valves and Automatic Shutoff Devices for
Hot Water Supply Systems, ANSI Z21.22, orThe ANSI/
ASME Boiler and Pressure Vessel Code, Section IV(
Heating Boilers). This pressure relief valve must be
capable of an hourly Btu rated temperature steam dis-
charge of 140,000 Btuh for 660 EF-(O)). Multiple
valves may be used. The pressure relief capacity must
not exceed 150 psi. No valve shall be placed between
the relief valve and the water heater. The relief valve
must be installed such that the discharge will be con-
ducted to a suitable place for disposal when relief
occurs. No reducing coupling or other restriction may
be installed in the discharge line. The discharge line
must be installed to allow complete drainage of both the
valve and the line. If this unitis installed with a separate
storage vessel, the separate vessel must have its own
temperature and pressure relief valve. This valve must
also comply with The Standard for Relief Valves and
Automatic Gas Shutoff Devices for HotWater Supply
Systems, ANSI Z21.22. (in the U.S. only). A tempera-
ture relief valve is not required, but if one is used,do not
install the valve with the probe directly in the flow of
water. This may cause unwarranted discharge of the
valve. Piping and components connected to the water
heater shall be suitable for use with potable water. Toxic
chemicals, such as those used for boiler treatment, shall
not be introduced into the potable water. A water heater
used to supply potable water may not be connected to
any heating system or components previously used with
a nonpotable water heating appliance. When water is
required in one part of the system at a higher tempera-
ture than in the rest of the system, means such as a mix-
ing valve shall be installed to temper the water to reduce
the scald hazard.
• Flush water through the pipe to clean out metal pow-
der, sand and dirt before connecting it.
24
• Perform the following insulation measures for preven-
tion of freezing.
• Take appropriate heat insulation measures (e.g.,
wrapping with heat insulation materials, using elec-
tric heaters) according to the climate of the region to
prevent from freezing.
• Make sure that there are no water leaks from the cold
and hot water supply pipes, then insulate the pipes
completely.
• Be sure to also completely insulate the water supply
valve and the cold and hot water connections on the
water heater (refer to the Fig. 24).
• Do not cover the water drain plug with insulation so
that water in the pipe can be drained (refer to the Fig.
24).
Fig. 24
• Use a union coupling or flexible pipe for connecting
the pipes to reduce the force applied to the piping.
• Do not use piping with a diameter smaller than the
coupling.
• When feed water pressure is too high, insert a
depressurizing valve, or take water hammer preven-
tion measures.
• Avoid using joints as much as possible to keep the
piping simple.
• Avoid piping in which an air lock can occur.
If installing the unit on a roof:
If the unit is installed on a roof to supply water to the lev-
els below, make sure that the water pressure supplied
to the unit does not drop below 29 psi. It may be nec-
essary to install a pump system to ensure that the water
pressure is maintained at this level. Check the pressure
before putting the unit into operation. Failure to supply
the proper pressure to the unit may result in noisy oper-
ation, shorter lifetime of the unit, and may cause the unit
to shut down frequently.
6 720 644 063