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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 flow preventers, etc...to control these typgs of
_roblems. When these devices are not equip_sed with an internal
oy-pass, and no other measures are taken, me 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
rel'ef valve is reached, the
valve will relieve the excess pressure. The temperature-pressure
reed valve is not intended for the €o_st_nt 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 taaks 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
Number
153.331020
153.331050
2
5
Dimettsiom in Inches
Diameter
Length
8 inches
12_ inches
11 inches
14_ inches
Pipe Fittir_g
On Tank
_" Male
_" Male
COLD
WATERHF_TER
COLD WATER
INLET FITTING
HOT
COLD
WATER HEATER
(3)
COLD WA'I--_
pRESSURE
INLET FrI'rlNG
REDUCING
VALVE WITH
BY-PASS
WATER
SHUTOFF
RECOHFtEHDED
IHISTALLATIOH
(V_nCAL MOUNT._)
P,.OOR, CEtUNG
lOST,ETC.
STRAPPING
O)
PRESSURE
REDUCING
INLET COLD
VALVE WITH
WATER
BY4PASS
SHUTOFF
Expansion
Tank Sizing Chart
Inlet*
Water
Pressure
30
40
50
66
82
Ex_,_onn--o; 40psi
2
2
2
5
5
Capacity
50psi
2
2
2
5
5
Needed
60psi
2
2
5
5
5
70psi
2
2
5
5
5
80psi
2
5
5
5
5
Water Heater Capacity (Gallons)
*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 ti_e inlet water pressure is higher than 40 psi, the
expansion
tanks a'r pressure must be adjusted to match that
pressure, but must not be higher than 80 psi.
ALTERNATE RECOHMENDED
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.
Condensation
causes sizzling and popping with the burner area
during heating and coolin_ periods and should be considered
normal. See "Condensation
section.
28
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