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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 flowpreventers,
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 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 int_ndecl for the constant
relief of thermal
expm'tsion.
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
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
WATERHEATER
(3)
• COLDWATER
PRESSURE
INLETFITTING
REDUCING
VALVE WITH
BY-PASS
(i)
1
EXPANSION
TANK
(z)
PRESSURE G AUGE
WATER
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
WATER HEATER
FLOOR, CEILING
COLD WATER
JOIST, ETC.
INLET FITTING
HOT
COLD
STRAPPING
(1)
EXPANSION
(3)
PRESSURE
REDUCING
VALVE WITH
BY-PASS
INLET COLD
WATER
SHUTOFF
Expansion Tank Sizing Chart
Water Heater Capacity (Gallons)
Inlet*
Water
Pressure
40psi
50psi
60psi
70psi
80psi
6
10
20
30
40
Expansion
Tank
2
2
2
2
2
Capacity
2
2
2
2
2
Needed
2
2
2
2
2
2
2
2
2
2
2
2
2
2
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.
(2)
PRESSURE G AUGE
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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