June 30, 2003 a new standard and a new design will be required
for all gas-fired residential water heaters of 75,000 BTUs or less
manufactured in the U.S. ANSI Standard Z21.10.1-2001 requires that
the design of such water heaters "shall not ignite flammable
vapors outside the water heater created by the spilling of ...
gasoline onto the floor."
While the new water
heater design is in response to the ignition of flammable vapors by gas-fired
water heaters, the issue is not whether gas-fired water heaters in
homes and businesses throughout the U.S. are safe and reliable. They
are not defective, nor do they present an unreasonable risk of injury.
In many cases, the water heater is the most consistently performing
appliance in the home.
The problem lies in consumers
storing flammable liquids, such as gasoline, next to or near water
heaters. The result, says the Consumer Product Safety Commission (CPSC),
is flammable vapors - the byproduct of the evaporation of flammable
liquids, such as gasoline, due to accidental spills or misuse - coming
in contact with an ignition source and causing a fire or explosion.
CPSC says that traditionally designed gas water heaters, which draw combustion
air through vents at the bottom of the appliance, have occasionally ignited
these vapors. CPSC has associated nearly 2,000 fires a year, 17 deaths, and
316 injuries to flammable vapor fires and water heaters. However, it's important
to note that only 5 percent of fires involving ignition of flammable vapors
in homes were related to the gas water heaters. About 75 percent of the fires
were due to spills of improperly stored gasoline or the improper use of gasoline.
To address the issue, a group
of water heater manufacturers came together to form the Joint Research
and Development Consortium. The goal was to develop a permanent, technical
solution to the flammable vapor ignition resistance (FVIR) problem.
This ongoing, voluntary industry
approach to developing FVIR technologies, says David R. Martin, vice
president of Marketing for Rheem Water Heaters in Montgomery, AL, U.S.,
calls for manufacturers to invest their own resources in new product
designs and the methods to test them. He says, "The new ANSI standard
is a milestone because it represents an industry-leading approach that
will ensure the long-term reliability of the new FVIR technologies."
Thus, as of June 30, all
30-, 40-, and 50-gal atmospherically vented water heaters will have
to pass a flammable vapor test designed to keep water heater pilot
lights and burners from igniting spilled gasoline. Phase 2 of the Standard
begins July 1, 2004, with 30-, 40-, and 50-gal power-vented heaters,
and Phase 3 covers the remaining models starting July 1, 2005. (Canada's
Phase 1 will begin Jan. 1, 2004 - 6 months after the U.S. rollout).
The new design calls for
a sealed combustion chamber with an air inlet, where air flows through
the arrestor plate, which is a perforated piece of steel. If any flammable
vapors enter the combustion chamber, the arrestor plate, or flame arrestor,
controls the burning of the vapors and prevents the flames from escaping
the unit into the room, thus avoiding a fire or explosion. A bench
standard that calls for protection of the water heater from lint, dust,
and oil, or LDO, was attached to the flammable vapor standard after
it was determined in test studies that LDO contamination could be a
According to Mr. Martin,
the new FVIR standard will not affect the current installed base of
residential gas-fired water heaters, or any unsold water heater made
before the effective date.
However, says Mr. Martin,
at this juncture, it is difficult to pinpoint how the industry-wide
compliance with the ANSI standard will impact the residential water
heater market this year. One observation he does make is that the new
FVIR designs will cost more to produce and must necessarily be sold
at significantly higher price points.
Design differences may be the largest difference, says Mr. Martin. Early in
the development process, flammable vapor resistance was achieved with the use
of arrestor technologies. As a result, all the new water heaters will incorporate
some form of flame arrestor plate to shield the water heater burner and prevent
its flame from spreading beyond the arrestor. "But while some type of
arrestor will be common to every new FVIR unit, there still will be many design
differences in the products that come to market after June 30, 2003," Mr.
Martin says. "Over time, these critical variations may influence brand
loyalties among plumbing and HVAC contractors."
One design difference within
the flame arrestor plate is that the plate can pass the test necessary
to meet the ANSI standard, but the standard does not cover a sustained
flammable vapor incident. Meanwhile, says Mr. Martin, shutting off
the gas supply, as all designs will do, does not stop combustion in
the chamber. Thus, Rheem's new Guardian System calls for a complete
shutoff of the combustion chamber when a flammable vapor incident is
detected. The system is intentionally designed without a user interface
or "reset" feature. As a result, says Mr. Martin, the homeowner
is spared any concern with "nuisance" shutdowns or maintenance
during the usual life of the product.
Despite warning labels that
make it clear that consumers should never store gasoline near their
water heater, and past aggressive programs to educate and warn consumers
about the dangers of storing gasoline near their water heaters, such
as the Gas Appliance Manufacturers Association's consumer awareness
program in 1993, it's safe to assume that consumer responsibility will
wane and accidents will happen.
What was once considered
an unsolvable safety hazard has now been solved. And unlike past CPSC
rulings and regulations, in this case, the water heater industry was
given the opportunity to voluntarily develop the technology necessary
to achieve a permanent solution. That's a refreshing change from the
CPSC simply handing down regulation, as it has done in the past. The
voluntary approach results in manufacturers taking control of their
destiny and the products they manufacture.