8
INSTALLATION
If the water heater is to be installed directly on carpeting,
the water heater shall be installed on a metal or wood
panel extending beyond the full width and depth of the
water heater by at least 3 in. (7.6 cm) in all directions
or, if the water heater is to be installed in an alcove or
closet, the entire floor must be covered by a wood or
metal panel.
CORROSIVE ATMOSPHERES
The air in beauty shops, dry cleaning establishments,
photo processing labs, and storage areas for liquid and
powdered bleaches or swimming pool chemicals often
contain halogenated hydrocarbons.
An air supply containing halogenated hydrocarbons may
be safe to breathe, but when it passes through a gas
flame corrosive elements are released that will shorten
the life of any gas burning appliance.
Propellants from common spray cans or gas leaks from
A/C and refrigeration equipment are highly corrosive
after passing through a flame.
The water heater warranty is voided when failure of the
heater is due to operation in a corrosive atmosphere.
THERMAL EXPANSION
Determine if a check valve exists in the inlet water line.
It may have been installed in the cold water line as
a separate back flow preventer, or it may be part of a
pressure reducing valve, water meter or water softener.
A check valve located in the cold water inlet line can
cause what is referred to as a ”closed water system”.
A cold water inlet line with no check valve or back flow
prevention device is referred to as an ”open” water
system.
As water is heated, it expands in volume and creates
an increase in the pressure within the water system.
This action is referred to as ”thermal expansion”. In an
”open” water system, expanding water, which exceeds
the capacity of the water heater, flows back into the city
main where the pressure is easily dissipated.
A ”closed water system”, however, prevents the
expanding water from flowing back into the main supply
line and the result of ”thermal expansion” can create
a rapid, and dangerous pressure increase in the water
heater and system piping. This rapid pressure increase
can quickly reach the safety setting of the relief valve,
causing it to operate during each heating cycle. Thermal
expansion, and the resulting rapid, repeated expansion
and contraction of components in the water heater and
piping system can cause premature failure of the relief
valve and possibly the heater itself. Replacing the relief
valve will not correct the problem!
The suggested method of controlling thermal expansion
is to install an expansion tank in the cold water line
between the water heater and the check valve. The
expansion tank is designed with an air cushion built
in that compresses as the system pressure increases,
thereby relieving the over pressure condition and
eliminating the repeated operation of the relief valve.
Other methods of controlling thermal expansion are
also available. Contact your installing contractor, water
supplier, or plumbing inspector for additional information
regarding this subject.
WATER CONNECTIONS
Refer to illustration on page 11 for suggested typical
installation. The installation of unions or flexible
connectors is recommended on the hot and cold water
connections so that the water heater may be easily
disconnected for servicing if necessary. If flexible water
connections are used, they must comply with the standard
for flexible Water Connectors, ASME A112.18.6/CSA-
B125.6. The HOT and COLD water connections are clearly
marked on the water heater. Install a shutoff valve in the
cold water line near the water heater.
IMPORTANT
All models are equipped with front and side panels, it is
recommended that the hot and cold water piping have a
minimum vertical height of 10 inches (25.4 cm) from the
top of the water heater before transitioning into any elbow.
This vertical height is needed in order to provide adequate
clearance for Side Panel installation and removal.
To gain access to the hot and cold water connections
the side panels need to be removed. The side panels are
secured on the top of the water heater with fastening
pegs (see illustration). Pull the side panels either
outwards or upwards to release panels from pegs.
RELIEF VALVE
The pressure rating of the relief valve must not exceed
150 psi (1,034 kPa), the maximum working pressure of the
water heater as marked on the rating plate.
The Btu/h rating of the relief valve must equal or exceed
the Btu/h input of the water heater as marked on its rating
plate.
Position the outlet of the relief valve above a suitable open
drain to eliminate potential water damage. Piping used
should be of a type approved for hot water distribution.
The discharge line must be no smaller than the outlet of
the valve and must pitch downward from the valve to allow
complete drainage (by gravity) of the relief valve and
discharge line.
The end of the discharge line should not be threaded or
concealed and should be protected from freezing. No valve
of any type, restriction, or reducer coupling should be
installed in the discharge line.
TO FILL THE WATER HEATER
Make certain that the drain valve is closed, then open the
shut-off valve in the cold water supply line.
Open each hot water faucet slowly to allow the air to vent