Use and Care Manual

41
8 Connecting the Water Supply
• Installation and service must be performed by a
qualified plumber.
• In the Commonwealth of Massachusetts, this
product must be installed by a licensed plumber
or gas fitter in accordance with the Massachusetts
Plumbing and Fuel Gas Code 248 CMR Sections
2.00 and 5.00.
• Observe all applicable codes.
Installation location
• If the Water Heater is installed in a closed water
supply system, such as one having a backflow
preventer on the cold water 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.
• If installing the Water Heater on a roof:
If the Water Heater is installed on a roof to supply
water to the levels below, make sure that the
water pressure supplied to the Water Heater
does not drop below 29 psi. It may be necessary
to install a pump system to ensure that the water
pressure is maintained at this level or to decrease
the flow rate by adjusting the water fixture.
Check the pressure before putting the Water
Heater into operation.
Failure to supply the proper pressure to the
Water Heater may result in noisy operation,
shorter lifetime of the Water Heater, and may
cause the Water Heater to shut down frequently.
Valve
• A pressure relief valve must be installed near the
hot water outlet that is rated in accordance with
and complying with either The Standard for Relief
Valves and Automatic Shutoff Devices for Hot
Water Supply Systems, ANSI Z21.22, or The ANSI/
ASME Boiler and Pressure Vessel Code, Section IV
(Heating Boilers).
• A pressure relief valve must be capable of an
hourly Btu rated temperature steam discharge
capacity of 199,900 Btu/h.
Multiple valves may be used.
The pressure relief capacity must not exceed 150
psi.
• Do not install a shutoff valve between a relief
valve and the Water Heater.
The relief valve must be installed such that the
discharge will be conducted 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 Water Heater is installed with a separate
storage vessel, the separate vessel must have its
own temperature and pressure relief valve.
• Temperature and pressure relief valve must also
comply with The Standard for Relief Valves and
Automatic Gas Shutoff Devices for Hot Water
Supply Systems, ANSI Z21.22 (in the U.S. only).
• A temperature 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.
• When the system requires water for space
heating at temperatures higher than required for
other uses, a means such as a mixing valve shall
be installed to temper the water for those uses in
order to reduce scald hazard potential.
Potable water
• 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.
8.1 Installation
Connnecting water supply
• Flush water through the pipe to clean out metal
powder, sand and dirt before connecting it.
• Use a union coupling or flexible pipe for
connecting the pipes to reduce the force applied
to the piping.
NOTE
• Do not use piping with a diameter
smaller than the coupling.
• Avoid using joints as much as
possible to keep the piping simple.
• Avoid piping in which an air holdup
can occur.
8.1.1 Guidelines
Connecting the Water Supply