Instructions / Assembly
lp-547 Rev. 1.29.16
6
C. Water Chemistry Requirements
Chemical imbalance of the water supply may aect eciency
and cause severe damage to the water heater and associated
equipment. HTP recommends having water quality
professionally analyzed to determine whether it is necessary to
install a water softener. It is important that the water chemistry
on both the domestic hot water and central heating sides are
checked before installing the water heater, as water quality
will aect the reliability of the system. In addition, operating
temperatures above 135
o
F will further accelerate the build-
up of lime scale and may shorten the service life of the water
heater. Failure of a water heater due to lime scale build-up,
low pH, or other chemical imbalance IS NOT covered by the
warranty.
Outlined below are water quality parameters that need to be
met in order for the system to operate eciently for many years.
Water Hardness
Water hardness is mainly due to the presence of calcium and
magnesium salts dissolved in water. The concentration of these
salts is expressed in mg/L, ppm, or grains per gallon as a measure
of relative water hardness. Grains per gallon is the common
reference used in the US 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 classied as very soft, slightly
hard, moderately hard, or hard based on its hardness number.
The minerals in the water precipitate out as the water is heated
and cause accelerated lime scale accumulation on a heat transfer
surface. This lime scale build-up may result in premature failure
of the water heater.
Water that is classied as hard and very hard must be softened
to avoid water heater failure.
CLASSIFICATION MG/L OR PPM GRAINS/GAL
Soft 0 - 17.1 0 - 1
Slightly Hard 17.1 - 60 1 - 3.5
Moderately Hard 60 - 120 3.5 - 7
Hard 120 - 180 7 - 10.5
Very Hard 180 and over 10.5 and over
If the hardness of the water exceeds the maximum level of 12
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 aect 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: Less than 12 grains
Chloride levels: Less than 100 ppm
pH levels: 6 - 8
TDS: Less than 2000 ppm
Sodium: Less than 20 mG/L
Failure of electric elements due to lime scale build-up on the
heating surface, low pH, or other imbalance IS NOT covered
by the warranty.
Dielectric unions or galvanized steel ttings must not be used
in a system with this water heater. Doing so WILL VOID the
warranty. It is recommended to use only copper, brass, or
stainless steel ttings. Teon thread sealant must be used on
all connections.
1. Install a shut-o or check valve or both on the inlet
connection on the top of the heater. Connect the cold water
supply line to the shut-o valve or check valve. Refer to piping
Applications, this manual.
Do not apply heat to the Hot or Cold water heater connections.
If sweat connections are used, sweat tubing to the adapter
before tting adapter to the water connections on the
heater. Any heat applied to the water heater connections
will permanently damage the dip tube and/or heat traps.
Damages due to improper installation practices ARE NOT
covered by warranty.
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 sealing
compound on all mechanical plumbing connections.
It is recommended to use unions on the hot and cold water
connections to easily disconnect the water heater for
servicing.
Part 3 - Piping