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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-offs, 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
_roblems. When these devices are not equipped with an internal
y_pass, and no other measures are taken, the devices cause the
water system to be closed. As water is heated, it expands (ther-
mal expansion) 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 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.
Thermal expansion tanks are available from Sears stores and
through the Sears Service Centers. Contact the local plumbing
inspector, water supplier and/or the Sears Service Center for
assistance in controlling these situations.
Thermal Expansion Tank Specifications
Model Tank Capacity !Dimensions in Inches [ Pipe Fitting ]
Numbe r , !nGall0ns_ D!ameter I Length On, Tank I
153:33!O20 2 . 8inches 12_inches; _',Male
153.331050 5 i 11 inches 14_ inches Y_'Male
HOT COLD
WATER HEATER
COLD WATER
INLET FI'H'ING
HOT
WATERHEATER (3)
• COLDWATER PRESSURE
,INLETFITTING REDUCING
VALVEWITH
BY-PASS
(1)
EXPANSION(_
TANK
PRESSUREGAUGE COL
WATER
SHUTOFF
RECOHMENDED INSTALLATION
(VERTICAL MOUNTING)
FLOOR, CEILING
JOIST,ETC.
STRAPPING
0)
EXPANSION
O)
PRESSURE
REDUCING INLETCOLD
VALVEWITH WATER
BY-PASS SHUTOFF
Expansion Tank Sizing Chart
Inlet*
Water
Pressure
Expansion
Tank 40psl
Capacity 50psi
Needed 60psi
70psi,
80psi
Water Heater Capacity (Gallons)
30 40 50
2 2 2
2 2 2
2 2 5
12 2 5
2 5 5
66 82
5 5
5 5
5 5
5 5
5 5
*Highest recorded inlet water pressure m a 24 hour period or
regulated water pressure.
NOTE: Expansion tanks are pre-charged with a 40 psi air
charge. If the i,nlet 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.
(2) !
PRESSUREGAUGE
ALTERNATE RECOMMENDED
INSTALLATION
(HORIZONTAL HOUNTING)
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 heating and cooling periods and should be considered
normal. See "Condensation" section.
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