Gas Supply - Rheem Raypak Hi Delta P902C Installation & Operating Instructions Manual

heater due to lime scale build up on the heating sur-
face is non-warrantable. The manufacturer of the pool
heater has no control of the water quality, especially
the TDS levels in your system. Total dissolved solids in
excess of 1,500 ppm will accelerate lime and scale for-
mation in the heat exchanger. Heat exchanger failure
due to total dissolved solids in excess of 1,500 ppm is
a non-warrantable condition.
NOTE: Failure of a heat exchanger due to lime
scale build-up on the heating surface, low pH or
other chemical imbalance is non-warrantable.
Water Hardness
Water hardness is mainly due to the presence of cal-
cium and magnesium salts dissolved in the water. The
concentration of these salts is expressed in mg/l, ppm
or grains per gallon, as a measure of relative hardness
of water. Grains per gallon is the common reference
measurement used in the U.S. water heater industry.
Hardness expressed as mg/L or ppm may be divided
by 17.1 to convert to grains per gallon. Water may be
classified as very soft, slightly hard, moderately hard
or hard based on its hardness number. The salts in
water will precipitate out when the water is heated and
will cause accelerated lime and scale accumulation on
a heat transfer surface.
Raypak water heaters can operate lime/scale-free
using potable water with a hardness not exceeding 25
grains per gallon. Proper operation is achieved by set-
ting the temperature rise/water flow per the guidelines
in the installation instructions. If the hardness of the
water exceeds the maximum level of 25 grains per gal-
lon special measures must be taken to adjust flow and
temperature rise. Water should be softened to a hard-
ness level no lower than 5 grains per gallon. Water
softened as low as 0 to 1 grain per gallon may be
under-saturated with respect to calcium carbonate
resulting in water that is aggressive and corrosive.

Gas Supply

DANGER: Make sure the gas on which the heater
will operate is the same type as specified on the
heater's rating plate.
Gas piping must have a sediment trap ahead of the
heater gas controls, and a manual shut-off valve lo-
cated outside the heater jacket. It is recommended
that a union be installed in the gas supply piping adja-
cent to the heater for servicing. A pounds-to-inches
regulator must be installed to reduce the gas supply
pressure to a maximum of 10.5 in. WC for natural gas
and 13.0 in. WC for propane gas. The regulator should
be placed a minimum distance of 10 times the pipe
diameter up-stream of the heater gas controls. Refer
to Table J for maximum pipe lengths.
Gas Supply Connection
CAUTION: The heater must be disconnected from
the gas supply during any pressure testing of the gas
supply system at test pressures in excess of 1/2 psi
(3.45 kPa).
The heater must be isolated from the gas supply pip-
ing system by closing the manual shut-off valve during
any pressure testing of the gas supply piping system
at test pressures equal to or less than 1/2 psi (3.45
kPa). Relieve test pressure in the gas supply line prior
to reconnecting the heater and its manual shut-off
valve to the gas supply line. FAILURE TO FOLLOW
THIS PROCEDURE MAY DAMAGE THE GAS
VALVES. Over pressurized gas valves are not cov-
ered by warranty. The heater and its gas connections
shall be leak-tested before placing the appliance in
operation. Use soapy water for leak test. DO NOT use
an open flame.
Fig. 27: Gas Supply Connection
CAUTION: Do not use Teflon tape on gas line pipe
thread. A pipe compound rated for use with natural
and propane gases is recommended. Apply
sparingly only on male pipe ends, leaving the two
end threads bare.
CAUTION: Support gas supply piping with
hangers, not by the heater or its accessories. Make
sure the gas piping is protected from physical
damage and freezing, where required.
25