State Water Heaters RESIDENTIAL ELECTRIC WATER HEATER, Руководство по обслуживанию

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RESIDENTIAL ELECTRIC WATER HEATER
SERVICE HANDBOOK
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Technical Training Department
13 of 36 Residential Electric Svc Handbook
Ashland City, Tennessee ©2004 STC082
SURFACE MOUNTED THERMOSTAT (S) AND HIGH LIMIT (S)
The thermostats and high limits are held against the side of the tank. As the tank surface heats
or cools, a metal disc inside of the control expands or contracts to open or close electrical
contacts in the controls. They will satisfy within 10
°
F of setting. The tank surface has to cool
8 - 15
°
F to reactivate these controls.
Thermostat models WH9-6 and WH10-7 include a “high limit” or energy cut off (ECO) switch as
an integral part of the thermostat. The ECO is attached at the top of the thermostat and has a
red reset button in the middle. The ECO will shut off power to the elements if the top of the
water heater tank reaches 180° F. temperature. The ECO must be manually reset when the
tank cools by pressing the red “reset “button.
Note: If the thermostat is not flat against the tank or the insulation has been removed
from the access area, the thermostat may not read the tank temperature properly and
may cause the ECO (high limit/reset button) to trip or the T & P valve to open as a result
of high water temperature in the tank.
TEMPERATURE ADJUSTMENT
All thermostats on residential electric water heaters are set by the factory at a temperature that
approximates 120°F (HOT) and are adjustable. Other temperature indicators are “A” = 130°F.,
“B” = 140°F., “C” = 150°F and VERY HOT 160°. Read all warnings before proceeding with a
temperature adjustment. On dual element models the upper and lower thermostats are
adjustable. It is normally not necessary to adjust the upper thermostat. If the upper thermostat
is adjusted, it should not be set higher than the lower thermostat. Some models have an
external temperature adjustment knob on the lower thermostat and the temperature indicators
are the same as the above.
WH9-2
WH9-6
WH10-7