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INSTALLATION
10 WATER QUALITY REQUIREMENTS
9
CAUTION: Chemical imbalance of the water supply may affect
efficiency and cause severe damage to the storage tank and
associated equipment.
ity professionally analyzed to determine whether it is neces-
sary 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 storage tank, as water
quality will affect the reliability of the system. Operating tem-
peratures above 135°F will further accelerate the build-up of
lime scale and may shorten the service life of the storage tank.
Failure of a storage tank due to lime scale build-up, low pH,
or other chemical imbalance IS NOT covered by the warranty.
Water Hardness
Water hardness is caused by calcium and magnesium in the
ground and surface water. If either of these minerals are present
in your drinking water in high concentrations, the water is consid-
ered hard. These minerals come from rock such as limestone that
dissolves in our river system. Hard water can build up and lead to
damaging the storage tank and associated piping. Water contain-
ing low concentrations of calcium or magnesium is called soft wa-
ter. Municipalities with soft drinking water often have higher inci-
dences of water pipe corrosion (low pH). The degree of hardness in
drinking water is commonly classified in terms of its concentration
of calcium carbonate. 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 measure-
ment 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 gal-
lon. Water may be classified as very soft, slightly hard, moderately
hard, or hard based on its hardness number.
Grains/Gal
< 1
1 - 3.5
3.5 - 7
7 - 10
> 10
If the water hardness exceeds 7 grains, the water will require a
water softener. Soften water to no lower than 5 grains. If the water
hardness is 0 to 1 grains, than the water will become aggressive
and corrosive.
R
recommends having water qual-
Water Hardness Scale
mg/L & ppm
Classification
< 17.1
17.1 - 60
Slightly Hard
60 - 120
Moderately Hard
120 - 180
> 180
pH of Water
pH is a measure of the acidity / basicity of an aqueous solution.
Solutions with a pH less than 7 are said to be acidic and solutions
with a pH greater than 7 are basic or alkaline. Pure water has a
pH very close to 7. Neutral 7pH is desirable for water heat applica-
tions. Corrosion damage and tank failures resulting from water
pH levels of lower than 6 or higher than 8 ARE NOT covered by
the warranty. The ideal pH range for water used in a storage tank
or a water heater system is 7.2 to 7.8.
Total Dissolved Solids
Total dissolved solids (TDS) is a measure of the combined content
of all inorganic and organic substances contained in a liquid in
molecular, ionized or micro-granular suspended form. Expressed
in ppm (parts per million).
Water with a high TDS concentration will greatly accelerate lime
and scale formation in the hot water system. Most high TDS con-
centrations precipitate out of the water when heated. This can
generate a scale accumulation that will greatly reduce the service
life of a storage tank.
The manufacturer of the storage tank has no control over water
quality, especially TDS levels in your system. Total dissolved solids
in excess of 2.000 ppm will accelerate lime and scale formation.
Storage tank failure due to total dissolved solids in excess of 2.000
ppm is a non-warrantable condition. Failure of a storage tank
due to lime scale build up IS NOT covered by the warranty.
Soft
Electrical conductivity
Hard
Very Hard
Sulphuric acid ions
Ammonia ions
The values above ensure proper operation of the system. Refer to
the limit values specified in the current standards and regulations
on the installation site.
11
Recommended Water Quality Measurements
Hardness
Chloride levels
pH levels
TDS
Sodium
REFERENCE VALUES
pH
less than 500 μS/inch (77°F)
Chlorine ions
Total iron
Alkalinity M
Sulphur ions
Silicon ions
INSTALLATION
7 grains
100 ppm
6-8
2000 ppm
20 mGL
6-8
less than 50 ppm
less than 50 ppm
less than 0.3 ppm
less than 50 ppm
none
none
less than 30 ppm
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