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Operating temperatures above 135
F will further accelerate the build-up of lime scale and may shorten the service life of the water
heater. Failure of the water heater due to lime scale build-up on the heating surface, low pH, or other chemical imbalance IS NOT
covered by the warranty.
Outlined on the following page are water quality parameters which need to be met in order for the system to operate efficiently 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
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 minerals in
the water precipitate out as the water is heated and cause accelerated lime scale accumulation on a heat transfer surface. This lime
o
scale build-up may result in premature failure of the water heater. Operating temperatures above 135
F will further accelerate the build-
up of lime scale and may shorten the service life of the water heater.
Water that is classified as hard and very hard must be softened to avoid water heater failure.
CLASSIFICATION
MG/L OR PPM
GRAINS/GAL
0 – 17.1
Soft
0 - 1
17.1 – 60
1 – 3.5
Slightly Hard
60 – 120
3.5 – 7.0
Moderately Hard
120 – 180
7.0 – 10.5
Hard
Very Hard
180 and over
10.5 and over
If the hardness of the water exceeds the maximum level of 7 grains per gallon, 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 affect water pH. The pH scale ranges from 0 to
14. Water with a pH of 7 is considered neutral. Water with a pH lower than 7 is considered acidic. Water 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 the 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 total
dissolved solids 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 a water heater.
The manufacturer of the water heater 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 on the element or heat exchanger. Water heater failure due to total
dissolved solids in excess of 2,000 ppm is a non-warrantable condition. Failure of a water heater due to lime scale build up IS NOT
covered by the warranty.
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6-8
TDS: 2000 ppm
Sodium: 20 Mgl
PART 3 – HEATER 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.
WHL-007 Rev. 10.3.14
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