Installation Manual

whl-007 Rev. 1.14.15
6
Part 3 - Piping
A. Plumbing
It is mandatory that all plumbing be done in accordance with
federal, local, and state plumbing codes and practices. Failure
to properly install the water heater WILL VOID the warranty. It
is also necessary to use both thread tape and pipe dope on all
mechanical plumbing connections.
When lling the water heater, open a hot water tap to release
air in the tank and piping. Failure to do so could lead to improper
water heater operation and damage to components.
DO NOT pipe this water heater with black iron, galvanized steel,
steel, or lead pipe. Doing so will result in premature product
failure and property damage, and WILL VOID the product
warranty.
B. Boiler Connections
Use two wrenches when tightening water piping at the heater.
Use one wrench to prevent the heater return or supply line
from turning. Failure to prevent piping connections from
turning could cause damage to water heater components.
Use a 1” nominal minimum pipe size when piping with zone
valves or circulators.
On the water heater, the boiler supply connects to the outlet of
the circulator. The circulator inlet is to be connected to the hot
outlet side of the boiler. Be sure that the arrow on the circulator
is facing the correct ow direction. (See pressure drop sizing for
circulator, this manual.) On the tank, the boiler return connects
to the return side of the boiler. The return(s) from heating
loop(s) should have a ow check or swing check valve installed
before the return pipe from the tank.
In a steam boiler, the tank supply must be connected to the
boiler well below the minimum water level. A strainer and drain
valve should be installed at the boiler for periodic draining of
scale and sludge. Banging and steam bound traps will occur if
the boiler water supplied to the heat exchanger has steam or is
slightly above the low water cut-o.
C. Domestic Piping Inlet
Never use dielectric ttings or galvanized steel ttings on any
domestic water connections. Use only copper or brass ttings.
Failure to do so will result in premature water heater failure.
Such failure IS NOT covered by warranty.
Use both thread tape and pipe dope to connect to the all
stainless steel 3/4” domestic inlet and outlet. A shut-o valve
between the city water supply and tank inlet is recommended
for ease of service.
It may be recommended to use a back ow preventer - check
local codes. If a back ow preventer or no return valve is used,
a thermal expansion tank must be installed on the cold water
supply between the tank and valve. If the tank is replacing a
tankless coil in the boiler, disconnect coil plumbing and use the
cold water inlet and hot water outlet pipes for the water heater.
D. Auxiliary Connections
The auxiliary connections are additional connections for a
recirculation line. These connections must be installed in
accordance with all local and national codes or any applicable
standard that prevails. Auxiliary connections are 3/4” on all
models. Never use dielectric unions or galvanized steel ttings.
Use only copper or brass ttings. Sealant must be used on all
connections.
If the hardness of the water exceeds the maximum level of 7
grains per gallon, the water should be softened to a hardness
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.
pH of Water
pH is a measure of relative acidity, neutrality, or alkalinity.
Dissolved minerals and gases aect water pH. The pH scale
ranges from 0 to 14. Water with a pH of 7 is considered neutral.
Water with pH lower than 7 is considered acidic. water with a
pH higher than 7 is considered alkaline. A neutral pH (around
7) is desirable for most potable water applications. Corrosion
damage and tank failures resulting from water pH levels of
lower than 6 or higher than 8 ARE NOT covered by warranty.
The ideal pH range for water used in a water heater is 7.2 to 7.8.
Total Dissolved Solids
Total Dissolved Solids (TDS) is a measurement of all minerals
and solids dissolved in a water sample. The concentration of
TDS is usually expressed in parts per million (ppm).
Water with a high TDS concentration will greatly accelerate
lime and scale formation in the hot water system. Most high
TDS concentrations precipitate out of the water when heated.
This can generate a scale accumulation that will greatly reduce
the service life of the water heater.
The manufacturer of the water heater has no control over
water quality, especially TDS levels in your system. TDS in
excess of 2000 ppm will accelerate lime and scale formation
on the element or the heat exchanger. Water heater failure
due to TDS in excess of 2000 ppm IS NOT covered by warranty.
Failure of a water heater due to lime scale build-up IS NOT
covered by warranty.
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6 - 8
TDS: 2000 ppm
Sodium: 20 mG/L
Never connect auxiliary connections to any system that uses
glycol or other solutions formulated for hydronic systems.
These auxiliary connections are to be used only in a potable
water system. Failure to follow this warning could result in se-
vere personal injury or death.