Kenmore POWER MISER 153.336851 - Manual (Page 22)

Troubleshooting Guide
Start Up Conditions
THERMAL EXPANSION
Water supply systems may, because of high line pressure, fre­
quent cut-offi, 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 problenis.
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 (thermal 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 the water heater’s temperature-pressure relief vive is
reached, the valve will relieve the excess pressure.
The tempeta-
tiu^reMure relief valve is not intended for the constant
relief of thermal eiqsanslon.
This is an unacceptable condition
and must be corrected.
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 in
the water system. Expansion tanks are available for ordering
through the Sears Service Center. Contact the local plumbing
inspector, water supplier, and/or the Sears Service (Jenter for
assistance in controlling these situations.
Thermal Expansion Tank Specifications
Model
Number
Tank Capacity
In Gallons
Dimensions in Inches
Diameter Length
153.331020 2 8 inches 12yj inches
153.331050 5 11 inches 145^ inches
Pipe Fitting
On Tank
y," Male
y;' Male
Expansion Tank Sizing Chart
Expulsion
Tank
Capacity
Needed
Inlet*
Water
Pressure
Water Heater Capacity (Gallons)
30 40 50 66 82
40psi 2 2 2 5 5
50psi 2 2 2 5 5
60psi 2 2 5 5 5
70psi 2 2 5 5 5
80psi 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 WATER HEATER
COLD WATER
j INLET FITTING
P)
PRESSURE
REDUCING
VALVE WITH
BVMSS
PRESSURE GAUGE 'i^LET COL
WATER
SHUTOFF
FKCOMMENDED INSTALLAHON
(VERTICAL MOUNTING)
WATOt HEATER
COLD WATER
INLET FITTING
FLOOR, CEIUNG
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
harmfol or dangerous conditions.
^ndensation causes sizzling and popping with the burner area
during heati^ and cooling periods and should be considered
normal. See “Condensation" section.
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