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Troubleshooting
Guide
Start Up Conditions
THERMAL
EXPANSION
Water supply systems may, because of high line pressure, fre-
quent cut-offs, the effects of water hammer and others, have
installed devices such as pressure reducing valves, check valves,
back flow preventers, etc. to control these types of problems.
When these devices are not equipped with an internal by-pass,
and no other measures are taken, the devices cause the water sys-
tem to be dosed. As water is heated, it expands (thermal expan-
sion) and dosed systems do not allow for the expansion of heat-
ed water.
The water within the water heater tank expands as it is heated
and increases the pressure of the water system. If the relieving
point of the water heater's remperature-pressure
relief valve is
reached, the valve will relieve the excess pressure. The tempera-
ture-pressure relief valve is not intended for the constant
re.rid of thermal expansion. This is an unacceptable condition
and must be corrected.
It is recommended that any devices installed which could create
a closed system have a by-pass and/or the system have an expan-
sion tank to relieve the pressure built by thermal expansion in
the water system. Expansion tanks are available for ordering
through the Sears Service Center. Contact the local plumbing
inspector, water supplier, and/or the Sears Service Center for
assistance in controlling these situations.
HOT
COLD
WATER HEA'RER
INLET FITTING
WATER HEATER
COLD WATER
INLET FITTING
HOT
COLD
0)
PRESSURE
REDUCING
VALVE
BY-PASS
WATER
SHUTOFF
RI_COHMENDED INSTALLATION
(VERTICAl.MOUNTING)
FLOOR, CEIUNG
Jo_"g, E TC.
STRAPPING
Thermal
Expansion Tank Specifications
Model
Tank Capacity
Dimensions in Inches Pipe Fitting
Number
In Gallons
Diameter
Length
On Tank
153.331050
5
11 inches 14_ inches
_" Male
(1)
EXPANSION
PRESSURE
REDUCING
INLET COLD
VALVEWITH
WATER
BY-PASS
SHUTOFF
!
Expansion Tank Sizing Chart
Inlet*
Ex_on
Water
Capacity
Pressure
Needed
40-80psi
Water Heater Capacity
(Gallons)
667371005
5
*Highest recorded inlet water pressure in a 24 hour period or
regulated water pressure.
NOTE: Expansion
tanks are pre-charged
with a 40 psi air
charge. If the inlet water pressure is higher than 40 psi, the
expansion tanks air pressure must be adjusted to match that
pressure, but must not be higher than 80 psi.
PRESSUREGAUGE
ALTERNATE RECOMMENDED
INSTALLATION
(HORIZONTAL MOUNTING)
STRANGE
SOUNDS
Possible noises due to expansion and contraction of some metal
parts during periods of heat-up and cool-down do not represent
harmful or dangerous conditions.
Condensation causes sizzling and popping with the burner area
during heatin_ and cooling periods and should be considered
normal. See Condeusation" s_ction.
23
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