A.O. Smith FMD 40 Manuale Utente
22
Excessive condensation may be noticed during the winter and
early spring months when incoming water temperatures are at their
lowest.
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.
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.
during the initial start-up. This is due to burning off of oil from metal
parts, and will disappear in a short while.
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.
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 local plumbing service agency to have a thermal expansion
tank installed.
closed systems to control the harmful effects of thermal expansion.
Contact a local plumbing service agency to have a thermal expansion
tank installed.
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.
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 “Condensation” in this section.
during heating and cooling periods and should be considered normal.
See “Condensation” in this section.
OPERATIONAL CONDITIONS
SMELLY WATER
In each water heater there is installed at least one anode rod (see
parts sections) for corrosion protection of the tank. Certain water
conditions will cause a reaction between this rod and the water.
The most common complaint associated with the anode rod is one
of a “rotten egg smell” in the hot water. This odor is derived from
hydrogen sulfi de gas dissolved in the water. The smell is the result
of four factors which must all be present for the odor to develop:
parts sections) for corrosion protection of the tank. Certain water
conditions will cause a reaction between this rod and the water.
The most common complaint associated with the anode rod is one
of a “rotten egg smell” in the hot water. This odor is derived from
hydrogen sulfi de gas dissolved in the water. The smell is the result
of four factors which must all be present for the odor to develop:
a. A concentration of sulfate in the supply water.
b. Little or no dissolved oxygen in the water.
c. A sulfate reducing bacteria which has accumulated within the
water heater (this harmless bacteria is nontoxic to humans).
d. An excess of active hydrogen in the tank. This is caused by the
corrosion protective action of the anode.
Smelly water may be eliminated or reduced in some water heater
models by replacing the anode(s) with one of less active material,
and then chlorinating the water heater tank and all hot water lines.
Contact the local water heater supplier or service agency for
further information concerning an Anode Replacement Kit and this
chlorination treatment.
models by replacing the anode(s) with one of less active material,
and then chlorinating the water heater tank and all hot water lines.
Contact the local water heater supplier or service agency for
further information concerning an Anode Replacement Kit and this
chlorination treatment.
If the smelly water persists after the anode replacement and
chlorination treatment, we can only suggest that chlorination or
aeration of the water supply be considered to eliminate the water
problem.
chlorination treatment, we can only suggest that chlorination or
aeration of the water supply be considered to eliminate the water
problem.
Do not remove the anode leaving the tank unprotected. By doing
so, all warranty on the water heater tank is voided.
so, all warranty on the water heater tank is voided.
“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.
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 a qualifi ed
technician.
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 a qualifi ed
technician.