For Your Information; Start Up Conditions; Operational Conditions - A.O. Smith Gdhe 50 Instruction Manual

start up condItIons

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.
therMal eXpansIon
As water is heated, it expands (thermal expansion). In a closed
system, the volume of water will increase. As the volume of
water increases, 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.

operatIonal condItIons

sMellY water
In each water heater there is installed at least one anode rod
(see Figure 1) 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. The smell is a result of four
factors which must all be present for the odor to develop:

for Your InforMatIon

45
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 water lines.
Contact the local water heater supplier or a qualified 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.
do not remove the anode leaving the tank unprotected. by
doing 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 flammable 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 flame near the faucet at the time it is open.