Automatic chemical dosing devices are usually more
efficient in heater water, unless controlled, they can
lead to excessive chlorine level which can damage
your heater.
Further advice should be obtained from your pool or
spa builder, accredited pool shop, or chemical suppli-
er for the correct levels for your water.
Water Hardness
Raypak water heaters can operate lime/scale-free
using potable water with a hardness not exceeding 25
gpg for models 1005 and 1505, and not exceeding 16
gpg for model 2005. Proper operation is achieved by
setting the temperature rise/water flow per the guide-
lines in the installation instructions. If the hardness of
the water exceeds the maximum level of 25 gpg spe-
cial measures must be taken to lower it. Water should
be softened to a hardness level no lower than 5 gpg.
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
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. The gas supply
pressureto theheater mustnot exceed10.5 in.WC for
natural gas or 13.0 in. WC for propane gas.
A pounds-to-inches regulator must be installed to
reduce the gas supply pressure if it is higher than
noted above. This regulator should be placed a mini-
mum distance of 10 times the pipe diameter upstream
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.
DANGER: Make sure the gas on which the heater
will operate is the same type as specified on the
heater’s rating plate.
CAUTION: The heater must be disconnected from
thegas 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 upstream 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 re-connecting the heater and its
manual shut-off valve to the gas supply line. FAILURE
TO FOLLOW THIS PROCEDURE MAY DAMAGE
THE GAS VALVE. Over-pressurized gas valves are
not covered by warranty. The heater and its gas con-
nections shall be leak- tested before placing the
appliance in operation. Use soapy water for leak test.
DO NOT use an open flame.
Fig. 18: Gas Supply Connection
CAUTION: Do not useTeflon tape on gas line pipe
thread. A pipe compound rated for use with natural
and propane gases is re commended. Apply
sparingly only on male pipe ends, leaving the two
end threads bare.
CAUTION: Support gas suppl y piping with
hangers, not by the heater or its accessories. Make
sure the gas piping is protected from physical
damage and freezing, where required.
19
of the heater gas controls. Refer toTable J on page 20
for maximum pipe lengths.

Gas Supply Connection

NOTE:Soft = 0–4 grains per gallon; Medium = 5–15
grains per gallon; Hard = 16–25 grains per gallon.
CAUTION: The XTherm is not for use with salt
water chlorinators—damage to heater may occur.