Sears 153.33645 - Manual (Page 22)

Start Up Conditions
THERMAL EXPANSION
Water supply systems may, because of iigli line pressure, fre­
quent cut-offs, the effects of water hammer and others, have
installed devices such as pressure reducing valves, check valves,
back flow preventers, 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 sys­
tem to be closed. As water is heated, it expands {thertaai expan­
sion) and closed systems do not allow for the expansion of heat­
ed 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 tire water heaters temperature-pressure relief valve is
reached, the valve will relieve the excess pressure. The tempera­
ture-pressure relief valve is not intended for the constant
relief of thermal expansion.
This is an unacceptable condition
and must be corrected.
It is recommetided 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 in
the water system. Expansion tanks ate available for ordering
through the Sears Service Center. Contact the local plumbing
inspector, water supplier, and/or the Sears Service Center for
assistance in controlling these situations.
Thermal Expansion Tank Specifications
Troubleshooting Guide
Model
Number
Tank Capacity
In Gallons
Dimensions in Inches Pipe Fitting
On Tank Diameter Length
153.331020 2 8 inches 12V^ inches '/j'' Male
153.331050 5 11 inches l4/j inches Male
Expansion Tank Sizing Chart
Expansion
Tank
Capacity
Needed
Met*
Water
Pres-sute
Water Heater Capacity (Gallons)
30 : 40 52 66 i 82
40 psi 2 2 2 5 i 5
50 psi 2 2 2 5 1 5
60 psi 2 2 ^ 5 5 1 5
JOpsi 2 2 = 5 5 5
SOpsi 2 5 1 5 5 5
^Highest recorded inlet water pressure in a 24 hour period or
regulated water pressure.
NOTE: Expansion tanks are prc-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.
WATER HEATER
COLD WATER
INLET FITTING FLOOR, CEILING
JOIST, ETC.
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 cooling periods and should be considered
normal. See “Condensation" section.
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