A.O. Smith ProMax GPDX-50, Instruction Manual

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25
FOR YOUR INFORMATION
START UP CONDITIONS
CONDENSATE
Whenever the water heater is filled with cold water, some
condensate will form while the burner is on. A water heater may
appear to be leaking when in fact the water is condensate. This
usually happens when:
a. A new water heater is fi lled with cold water for the fi rst time.
b. Burning gas produces water vapor in water heaters, particularly
high ef fi ciency models where fl ue temperatures are lower.
c. Large amounts of hot water are used in a short time and the re fi ll
water in the tank is very cold.
Moisture from the products of combustion condense on the cooler
tank surfaces and form drops of water which may fall onto the burner
or other hot surfaces to produce a “sizzling” or “frying” noise.
Because of the suddenness and amount of water, condensate water
may be diagnosed as a “tank leak”. After the water in the tank warms
up (about 1-2 hours), the condition should disappear.
Do not assume the water heater is leaking until there has been
enough time for the water in the tank to warm up.
An undersized water heater will cause more condensation. The water
heater must be sized properly to meet the family’s demands for hot
water including dishwashers, washing machines and shower heads.
Excessive condensate may be noticed during the winter and
early spring months when incoming water temperatures are at
their lowest.
Good venting is essential for a gas fi red water heater to operate
properly as well as to carry away products of combustion and water
vapor.
SMOKE/ODOR
It is not uncommon to experience a small amount of smoke and odor
during the initial start-up. This is due to burning off of oil from metal
parts, and will disappear in a short while.
CLOSED WATER SYSTEMS
Water supply systems may, because of code requirements or such
conditions as high line pressure, among others, have installed
devices such as pressure reducing valves, check valves, and back
fl ow preventers. Devices such as these cause the water system to
be a closed system.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a closed
system the volume of water will grow. As the volume of water
grows there will be a corresponding increase in water pressure due
to thermal expansion. Thermal expansion can cause premature
tank failure (leakage). This type of failure is not covered under the
limited warranty. Thermal expansion can also cause intermittent
temperature-pressure relief valve operation: water discharged from
the valve due to excessive pressure build up. The temperature-
pressure relief valve is not intended for the constant relief of
thermal expansion. This condition is not covered under the limited
warranty.
A properly sized thermal expansion tank should be installed on all
closed systems to control the harmful effects of thermal expansion.
Contact a plumbing service agency or your retail supplier regarding
the installation of a thermal expansion tank.
STRANGE SOUNDS
Possible noises due to expansion and contraction of some metal
parts during periods of heat-up and cool-down do not necessarily
represent harmful or dangerous conditions.
Condensation causes sizzling and popping within the burner area
during heating and cooling periods and should be considered normal.
See “Condensate” in this section.
OPERATIONAL CONDITIONS
“AIR” IN HOT WATER FAUCETS
HYDROGEN GAS: Hydrogen gas can be produced in a hot
water system that has not been used for a long period of time
(generally two weeks or more). Hydrogen gas is extremely
fl ammable and explosive. To prevent the possibility of injury under
these conditions, we recommend the hot water faucet, located
farthest away, be opened for several minutes before any electrical
appliances which are connected to the hot water system are used
(such as a dishwasher or washing machine). If hydrogen gas is
present, there will probably be an unusual sound similar to air
escaping through the pipe as the hot water faucet is opened.
There must be no smoking or open
fl ame near the faucet at the
time it is open.
HIGH WATER TEMPERATURE SHUT OFF SYSTEM
This water heater is equipped with an automatic gas shut-off
system. This system works when high water temperatures are
present. Turn “OFF” the entire gas supply to the water heater.
The high temperature shut-off is built into the gas control valve/
thermostat. It is non-resettable. If the high temperature shut-off
activates, the gas control valve/thermostat must be replaced.
Contact your gas supplier or service agency.