American Water Heater STCE3-52/80/119 ユーザーズマニュアル

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INSTALLATION CONSIDERATIONS
Servicing should only be performed by a Qualified Service Agent
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INSTALLATION CONSIDERATIONS
Installation information given in this Service Manual IS NOT a complete installation 
instruction. Installation information covered in this Service Manual has a limited focus as it 
applies to servicing. This Service Manual does not replace or supersede the Instruction 
Manual that came with the water heater. Always refer to the Instruction Manual that came 
with the water heater for complete installation instructions.
If the instruction Manual that came with the water heater is not on hand copies can be 
obtained from the manufacturers web site or by calling the toll free phone number shown on 
the back cover of this Service Manual.
CLOSED WATER SYSTEMS
Water supply systems may, because of code requirements or such conditions as high line 
pressure, among others, have installed devices such as pressure reducing valves, check 
valves, and back flow preventers. Devices such as these cause the water system to be a 
closed system.
Virtually all commercial and most residential water supply systems are closed systems 
today. Closed water systems will experience thermal expansion which, if not controlled with 
a properly installed and sized thermal expansion tank, can cause premature failure 
(leakage) of the water heater. Water heater failure (leakage) on closed systems where there 
is not a thermal expansion tank installed is not covered under the limited warranty.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a closed system the volume of water 
will grow when it is heated. As the volume of water grows there will be a corresponding 
increase in water pressure due to thermal expansion. Thermal expansion can cause 
premature tank failure (leakage). This type of failure is not covered under the limited 
warranty.
 Thermal expansion can also cause intermittent temperature-pressure relief valve 
operation: water discharged from the valve due to excessive pressure build up. This 
condition is not covered under the limited warranty.
 The temperature-pressure relief 
valve is not intended for the constant relief of thermal expansion.
A properly sized thermal expansion tank should be installed on all closed systems to control 
the harmful effects of thermal expansion.