Troubleshooting Guide
Start Up Conditions
THERMAL EXPANSION
Water supply systems may, because of such events as high line
pressure, lrequent cut-offs, the effects of water hammer among
others, have installed devices such as pressure reducingvalves,
check valves,back flowpreventers, etc-.to control these types of
problems. When these devicesare not equipped with an internal
by-pass,and no othermeasuresare taken, the devicescause the
water system to be dosed. As water is heated, it expands (ther-
mal expansion) and closed systemsdo 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 reiief valve is reached, the
valve will reheve the excess pressure. The tcml_-amrc-preasure
relief valve is not intended for the constant relief of thermal
_pansion. This is an unacceptable condition and must be cor-
rected.
It is recommended that any devices instal!ed 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 IDimensions in Inches Pipe Fitting
Number In Gallons Diameter Length On Tank
153.331020 2 8 inches 12_ inches _" Male
153.331050 5 1l inches 14_inches I _" Male
HOT COLD
WATERHEATBR
COLDWATER
INLETFII"nNG
HOT COLD
WATERHEATER O)
COLDWATER PRESSURE
INLETFITTING REDUCING
YALVEVVlTH
BY-PA_
รท:,g1
WA'_R
SHUTOFF
RECOMMENDED8q_g.LKnO_l
0mmCAL NOUN_)
FLOOR,CEIUNG
JOIS_,ETC.
STRAPPING
PRJESSURE INLET COLD
REDUCING WATER
VALVE WITH SHUTOFF
Expansion Tank Sizing Chart
Water Heater Capacity (Gallons)
Inlet*
Water
Pressure
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.
ALTERNATERECOMMENDED
IN_'DU.LAT_N
(HORIZONTAL M_NG)
STRANGE SOUNDS
Possible noises due to expansion and contraction of some metal
parts during periods of heat-up and cool-down do not represent
h_rofuL or dangerous conditions.
Condensation causes sizzling and popping with the burner area
during heating and cooling periods and should be considered
normal. See _Condensarion" section.
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