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Troubleshooting Guide
Start Up Conditions
THERMAL EXPANSION
Water supply systems may, because of such events as high line
pressure, frequent cut-off's, the effects of water hammer among
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 system to be closed• As water is heated, it expands (ther-
mal ex_,ansion) and closed systems do not allow for the expan-
sion of heated 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 temperature-pressure relief valve is reached, the
valve will relieve the excess pressure. The temperature-pressure
relief valve is not intended for the constant relief of thermal
expansion. This is an unacceptable condition and must be cor-
rected.
It isrecommended that any devicesinstalledwhich could createa
closed system havea by-passand/or the system have an expan-
sion tank to relieve the pressure built by thermal expansion.
Thermal expansion tanks are availablefrom Sears stores and
through the Sears Service Centers. Contact the local plumbing
inspector, water supplier and/or the Sears Service Center for
assistancein controlling thesesituations.
Thermal Expansion Tank Specifications
ModelTankCapacityOimensionsin nchesPipeFitting
Number InGallons Diameter Length On Tank
153.331020 2 8inches 12_inches _"Male
153.331050 5 11 inches 14_inches _"Male
HOT COLD
WATER HEATER
COLD WATER
INLET FITTING
HOT
WATER HEATER O)
• COLD WATER PRESSURE
INLET FI'I-NNG REDUCING
VALVEWITH
BY.PASS
WATER
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
FLOOR,CEILING
JOIST,ETC.
STRAPPING
(1)
EXPANSION
0)
PRESSURE
REDUCING INLET COLD
VALVE WITH WATER
BY-PASS SHUTOFF
Expansion Tank Sizing Chart
Water Heater Capacity (Gallons)
Inlet*
Water
Pressure
i 40psi
50psi
60psi
70psi
80psi
Expansion 30 40 50 66 82
Tank 2 2 2 5 5
Capacity 2 2 2 5 5
Needed 2 2 5 5 5
2 2 5 5 5
2 5 5 5 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 tank's air pressure must be adjusted to match that
pressure, but must not be higher than 80 psi.
PRESSURE GAUGE
ALTERNATE RECOMMENDED
INSTALLATION
(HORIZONTALMOUNTING)
STRANGE SOUNDS
Possible noises due to expansion and contraction of some metal
parts during periods of heat-up and cool-down do not represent
harmfial or dangerous conditions•
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