Kenmore POWER MISER 153.335816 - Manual (Page 28)

Troubleshooting Guide
Start Up Conditions
THERMAL EXPANSION
Water sufwly 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 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 intended for the constant 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 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
In Gallons
Dimensions in Inches Pipe Fitting
Number Diameter Length ; On Tank
153.331020 2 8 inches inches' Vy' Male
153.331050
_____ ^____
11 inches 14V^ inches "/ 4 " Male
Expansion Tank Sizing Chart
Inlet* Water Heater Capacity (Gallons)
Water
Expansion
Tank
Pressure 30 40 1 50 66 82
40psi 2 2 2 : 5 5
Capacity 50psi 2 2 2 ! 5 5
Needed 60psi 2 1 2 5 ' 5 5
70psi 2 1 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
rni n WATER HEATER
COLD WATER
INLET FITTING
(3)
PRESSURE
REDUCING
VALVE WITH
BY-PASS
(I)
EXPANSION
TANK
I
(2) ^ /'
PRESSURE GAUGE
SHUTOFF
RECOMMENDED INSTALLATION
(VERTICAL MOUNTING)
WATER HEATER
COLD WATER
INLET FITTING
FLOOR, CEILING
JOIST, ETC.
STRANGE SOUNDS
Possible noises due to expansion and contraction of some metal
arts during periods of heat-up and cool-down do not represent
larmful 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.
h
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