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Troubleshooting
Guide
Start Up Conditions
THERMAL
EXPANSION
Water sup, p ly systems may, because of such events as high line
pressure, trequent cut-offs, the effects of water hammer among
bthers, 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 dosed 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 excesspressure.
The temperature-pr_-,=,sure
relief valve is not intendedfor
the cohstant
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
ranks 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 I 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
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.
HOT
COLD WATERHEATER
(3)
COLDWAllER
PRESSURE
HEr
FITTING
REDUCING
VALVE WITH
B_
0)
1
EXPANSION
TANK
(3)
pRESSURE G AUGE
WATER
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
WATER HEATER
COLD WATER
INLET FITTING
FLOOR, C EILING
JOIST, E TC.
HOT
STRAPPING
(3)
PRESSURE INLETCOLD
REDUCING
VALVE WITH
WATER
0)
,*'_rms_ SHUTOFF
EXPANSION
•
i
TANK .
/
(z)
PRESSURE G AUGE
ALTERNATE RECOMMENDED
INSTALLATION
(HORIZONTAL MOUNTING)
STRANGE
SOUNDS
Possible noises due to expansion
and contraction
of some metal
parts during periods of beat-up and cool-down
do not represent
harmful or dangerous
conditions.
Condensation
causes sizzling and popping
with the burner area
during heatin_
and coolinl_ periods
and should be considered
normal. See Condensation
section.
23
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