Noritz extends 12-Yr/6,500-Hr Warranty


VALLEY, CA (September 22, 2010) — Tankless water heater
Noritz America recently extended its 12-year/6,500-hour warranty to
residential models used with controlled recirculation systems that
deliver hot water more quickly to the tap. The extension applies to all
Noritz residential tankless water heater products that feature the
company’s durable, commercial-grade
heat exchanger. Included are the new NR83-DVC concentric tankless water
heater, which made its debut this month, as well as the NR98, NRC111
and NR111.

“Twelve years typically translates into roughly 1.5 hours of
water heater combustion per day,” explains Bob Hitchner,
Senior Vice President – Sales, Marketing & Business Development
for Noritz. “A residential system that circulates warm water
for a couple of hours in the morning and another couple of hours in the
evening should make it for the full 12 years.”

To qualify for protection under the new residential recirculation
warranty, a Noritz tankless water heater must meet the following key

-The unit must have been installed on or after September 1, 2010, and
equipped with a controlled recirculation pump system that has been
installed in accordance with the Noritz Installation Manual.
-Water heater operational time must not exceed 12 years, or 6,500
hours, whichever comes first. (Note: Operational hours are the hours of
actual usage, as counted and stored in the water heater controller.)
-The recirculation pump must be controlled by an aquastat, which
activates the pump when the water temperature falls below a minimum set
point and deactivates it when the water temperature reaches the maximum
set point.

Noritz also strongly recommends the usage of demand-type timers and
sensors to confine pump activation to peak usage periods, further
reducing the load on the water heater.

“We love the luxury and water savings that a well-designed
recirculation system can deliver,” says Hitchner.
“But we also want homeowners and contractors to use common
sense when designing such systems.”

As Hitchner notes, most homes need hot water in the bedroom wing
between six and eight o’clock in the morning and eight to
eleven o’clock at night. Under these circumstances, the
recirculation loop may not be needed for the in-between times; or at
least the minimum set point in the loop can be lowered.

Why extend the warranty? Noritz residential tankless models used in
recirculation systems were previously excluded from the 12-year
warranty because of the heavy demands such systems impose on a water
heater, particularly its heat exchanger. If hot water is in constant
circulation – to be readily available at the tap or shower
– the water heater is operating 24/7 as well.

“We made the decision to extend the warranty after
extensively testing our commercial-grade heat exchangers,”
says Hitchner. “We clearly demonstrated to ourselves that
Noritz commercial heat exchangers could withstand the additional
operational time of a recirculation application.”

Begun in 2008, the tests referenced by Hitchner spanned 18 months and
involved side-by-side tests of three tankless water heater models: a
Noritz NR98-SV and two rival makes and models. To determine the effects
of hard water on each unit’s heat exchanger, the water
heaters were supplied with untreated city water at a hardness level
between 13 and 15 grains per gallon. The units were cycled on and off
around the clock, day after day, until failure of the heat exchanger.
The two competitive models failed after combustion lives of
approximately 1,200 and 2,760 hours. The Noritz NR98-SV with its
grade heat exchanger lasted 6,700 hours before failing.

Based on these results, Noritz calculated the following life
expectancies for the three tested water heaters:


Competitor A
Competitor B

Competitor A
Competitor B

Competitor A
About 60% less
Competitor B
About 80% less

TEST PROTOCOL: To estimate product lifespan (in years), Noritz (1) set
the temperature for both units to 140 degrees Fahrenheit, (2) supplied
both units with untreated city water with hardness levels between 13
grains per gallon (gpg) and 15 gpg, and (3) cycled the water on/off 24
hours a day during the test until a leak in each unit’s heat exchanger
was detected. The estimated lifespan (in years) of the heat exchanger
was calculated as follows: Hours of combustion for each product divided
by 365. (This calculation is based on average residential water usage
of one hour per day.)


Noritz attributes the superior performance of the NR98-SV test unit to
the thicker, commercial-grade copper used in its heat exchanger, as
well as to “subtle engineering nuances that improve the water
flow through the exchanger,” says Hitchner.

“It’s not good enough to extend a 12-year warranty
as just another marketing tool,” he continues. “We
needed to know whether our heaters are truly meant for this kind of
use. The tests validated that Noritz products with commercial-grade
heat exchangers could stand up to the heavy demands of a recirculation
system while also outperforming the competition.”

Softening the water: Another major determinant of life expectancy for a
water heater is the relative “hardness” of the
water supply. Hard water has a high scale content that can leave
deposits of calcium, magnesium and bicarbonate on pipe, valves and
fittings as well as water heating components. Difficult and costly to
remove, these highly insoluble deposits also hurt system efficiency
while boosting operating costs.

Water conditioning with a softener can help minimize scale deposits,
but a softener is not a viable option in every locale. Because these
devices discharge sodium and other chemicals into the water supply,
some jurisdictions have prohibited their use. Softeners also require
regular maintenance.

A recently unveiled alternative is the Noritz H2FLOW™. This
cartridge-based system produces no chemicals or salts, yet achieves a
99.6 percent effectiveness rating in scale prevention. Cartridge
replacement is required only once every two years.

H2FLOW technology fights scale buildup by changing the chemical
structure of the water as it flows through the device, converting hard
minerals into soft particles that will not adhere to plumbing-system
components – including the water heater. “By
preventing scale buildup, H2FLOW offers the added advantage of
maintaining the energy efficiency of the water heater over many years
of use,” says Hitchner.

“With the H2FLOW, even homeowners living in hard-water areas
can enjoy the
convenience of instant hot water with a well-designed controlled
recirculation system that enables their tankless water heater to
provide years of reliable service,” says Hitchner.
“That is the type of system our new warranty extension is
meant to protect.”

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