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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 reducing valves,
check valves,back flow preventers, etc-.to control these types of
problems. When these devicesare not equipped with an internal
by-pass,and no other measures are taken, the devicescause the
water system to be dosed. 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
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 I Dimensions 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
COLD WATER
INLET FII"nNG
HOT
COLD
WATER HEATER
O)
COLD WATER
PRESSURE
INLET FITTING
REDUCING
YALVE V VlTH
BY-PA_
÷:,g1
WA'_R
SHUTOFF
RECOMMENDED
8q_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.
23
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