5. Defrost Thermistor (cabinet) Malfunction Alarm (E8)
If the control board detects an open defrost thermistor, "E8" is displayed. When the control board detects a shorted defrost thermistor, a
•If this alarm appears, first make sure that the thermistor is properly connected to the control board.
•A shorted defrost thermistor is not detected by the control board during the 1st hour after power is turned on. To bypass the
Reset Options
The alarm automatically resets when one of the following conditions is met:
•The defrost thermistor is secured to the control board.
•The defrost thermistor is within normal operating range. For details, see "II.E. Thermistor Check."
•A functioning defrost thermistor is installed.
Possible Causes
•Trouble with the defrost thermistor. For checkout procedure, see "II.E. Thermistor Check."
•Trouble with the control board reading the defrost thermistor.
E8 Alarm |
|
Timer Start | E8 Alarm Timer Start |
Under 10 min. | 10 min. |
E8 (short circuit ) |
| |
Detection Point | E8 | |
122°F (50°C) | ||
Alarm | ||
| ||
E8 Alarm (open circuit) |
| |
Detection Point |
| |
|
Temperature Display
E8 Alarm (short circuit) Reset
E8 Alarm (open circuit) Reset
E8
Alarm
Temperature
Display
E8 | E8 |
Blinking | Blinking |
5a. Secondary Defrost Thermistor (Rail, not used)
The secondary defrost thermistor (located behind the wire cover) is not used for operation of the unit. It is used for control board programming and should not be removed. An "E8" alarm occurs when the secondary defrost thermistor is removed or fails. For details, see "III.A.6. Defrost Thermistor (cabinet) Malfunction Alarm (E8)."
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