4
MFH-I&S-02
If this water heater is installed in a closed water supply system, such as the one
having a back-flow preventer in the cold water supply, provisions shall be made
to control thermal expansion.
DO NOT
operate this water heater in a closed
system without provisions for controlling thermal expansion. Your water supplier
or local plumbing inspector should be contacted on how to control this situation.
After installation of the water lines, open the main water supply valve and fill
the water heater. While the water heater is filling, open several hot water
faucets to allow air to escape from the water system. When a steady stream
of water flows through the faucets, close them and check all water connections
for possible leaks.
NEVER OPERATE THE WATER HEATER WITHOUT FIRST
BEING CERTAIN IT IS FILLED WITH WATER.
This water heater can deliver scalding temperature water at any faucet in the
system. Be careful whenever using hot water to avoid scalding injury. Certain
appliances such as dishwashers and automatic clothes washers may require
increased temperature water. By setting the thermostat on this water heater to
obtain the increased temperature water required by these appliances, you may
create the potential for scald injury. To protect against injury, you should install
an anti-scald tempering valve in the water system. This valve will reduce point
of discharge temperature by mixing cold and hot water in branch supply lines.
Such valves are available from the local plumbing supplier. Please consult with
a plumbing professional.
GAS CONNECTIONS
The gas supply lines must meet all requirements of the National Fuel Gas Code
ANSI Z223.1-(Latest Edition) and/or in Canada CAN/CGA B149 Installation
Codes - (Latest Editions).
The minimum permissible gas supply pressure for the purpose of input
adjustment is 1.0" water column
(.25kPa)
above the operating manifold pressure.
See the rating plate and combination gas control for the manifold pressure and
gas type. The maximum permissible gas supply pressure is 14.0" water column
(3.5kPa)
for natural gas and liquefied petroleum gases/propane gas.
WARNING
Hydrogen gas can be produced in an operating water heater that
has not had water drawn from the tank for a long period of time
(generally two weeks or more). Hydrogen gas is extremely flammable.
To prevent the possibility of injury under these conditions, we
recommend the hot water faucet to be open for several minutes at the
kitchen sink before you use any electrical appliance which is connected
to the hot water system. If hydrogen is present, there will be an
unsual sound such as air escaping through the pipes as hot water
begins to flow. Do not smoke or have open flame near the faucet at
the time it is open.
WARNING
For protection against excessive temperatures and pressure, install
temperature and pressure protective equipment required by local codes,
but not less than a combination temperature and pressure relief valve
certified by a nationally recognized testing laboratory that maintains
periodic inspection of production of listed equipment or materials as
meeting the requirements of the Standard for
Relief Valves and Automatic
Gas Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22 or the
Standard CAN1-4.4. Temperature and Pressure
and the Standard
CAN1-
4.4, Temperature, Pressure, Temperature and Pressure Relief Valves
and Vacuum Relief Valves
. The combination temperature and pressure
relief valve shall be marked with a maximum set pressure not to
exceed the maximum working pressure of the water heater. The
combination temperature and pressure relief valve shall also have an
hourly rated temperature steam BTU discharge capacity not less than
the hourly rating of the water heater.
Install the combination temperature and pressure relief valve into the
opening provided and marked for this purpose on the water heater.
WARNING
NOTE:
Some models may already be equipped or supplied with a
combination temperature and pressure relief valve. Verify that the
combination temperature and pressure relief valve complies with local
codes. If the combination temperature and pressure relief valve does
not comply with local codes, replace it with one that does. Follow the
installation instructions above on this page.
Install a discharge line so that water discharged from the combination
temperature and pressure relief valve will exit within six (6) inches
(15.2 cm)
above, or any distance below the structural floor and cannot
contact any live electrical part. The discharge line is to be installed to
allow for complete drainage of both the combination temperature and
pressure relief valve and the discharge line. The discharge opening
must not be subjected to blockage or freezing.
DO NOT
thread, plug
or cap the discharge line. It is recommended that a minimum clearance
of four (4) inches
(10.2 cm)
be provided on the side of the water
heater for servicing and maintenance of the combination temperature
and pressure relief valve.
Do not place a valve between the combination temperature and pressure
relief valve and the tank.
