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Troubleshooting
Guide
Start
Up Conditions
THERMAL
EXPANSION
Water sup y
ysspJl s tems 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 flowpreventers, etc...to control these types of
problems. When these devices are not equipped with an internal
oy-pass, and no other measures are taken, the devices cause 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 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
I Tank Capacity
Dimensions in Inches : Pipe Fitting
Number
In Gallons
Diameter
Length
On Tank
153.331020
2
8 inches
12_ inches
_" Male
153.331050
5
11 inches 14_ inches
_" Male
HOT
COlD
WATER HEATER
COlD WATER
INLET FITTING
WATER HEATER
colD WATER
(3)
PRESSURE
, INLET FITTING
REDUCING
VALVEWITH
BY-PASS
(t)
1
EXPANSION
TANK
PRESSUREGAUGE
INLET COlD
WATER
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
FLOOR, CEILING
JOIS'l_, ETC.
STRAPPING
O)
EXPANSION
0)
PRESSURE
REDUCING
INLET COlD
VALVEWITH
WATER
BY-PASS
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
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.
18
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