U-Line Service and Repair, 3-15, 2275DWRWS/2275ZWC, THERMISTOR OUTAGE EXCEPT DWRWS & 2275ZWC

Section 3 - Service and Repair

COMPRESSOR
COMPRESSOR	TOP
CONDENSER	TOP
	COMPARTMENT
CONDENSER
	COMPARTMENT
SOLENOID VALVE	THERMISTOR
	THERMISTOR
SOLENOID VALVE
DRYER
DRYER
SOLENOID VALVE
SOLENOID VALVE
EVAPORATOR
EVAPORATOR
CAPILLARY TUBE
CAPILLARY TUBE
	BOTTOM
	BOTTOM
	COMPARTMENT
	COMPARTMENT
	THERMISTOR
	THERMISTOR
DRYER
DRYER
EVAPORATOR
EVAPORATOR
CAPILLARY TUBE	DWR052
CAPILLARY TUBE
	DWR052
Figure 10. 2275DWRWS/2275ZWC

REVIEW THE FOLLOWING NOTES FOR GENERAL INFORMATION.

•The unit is equipped with a four-minute compressor-off cycle.

•The mullion heater is energized on the 2175DWRR whenever the T3 temperature falls below 90°F.

Normal defrosting is based on a time and temperature scale. See chart on page 3-40. Defrost ends if evaporator thermistor reaches stop point or maximum time, whichever comes first.

THERMISTOR OUTAGE (EXCEPT DWRWS & 2275ZWC):

If the refrigerator thermistor (T1) fails, the unit will continue to operate based on a preset time interval of 10 minutes on and 30 minutes off. The display will show “ER.”

If the evaporator thermistor (T2) fails, the unit will operate except it will defrost solely on time and ignore the temperature reading. The display will show “ER.” If the ambient thermistor (T3) fails, the unit will always have the mullion heater energized. The display will show “ER.”

If T1 is not working, unit runs a preset time interval — 10 minutes ON, 60 minutes OFF.

If T2 is not working, unit runs a preset time interval — 10 minutes ON, 60 minutes OFF.

If either T3 or T4 is open, use 90 minutes for defrost length. These errors do not show on the display; they are only logged on the board.

SERVICE

To check to see which relays are currently operating, hold the COLDER key and press the ON/OFF key three times. When entering the sequence, keep the COLDER key pressed until you completely release the ON/OFF key for the third time. The display will cycle through a series of numbers to tell which relays are energized. For example, if the unit was cooling the bottom drawer the display would show 11 20 31 40 50 61 70. The first number is the relay number. In the second number, 1 means ON and 0 means OFF. The relay information can be found in the Control Section.

THERMISTOR OUTAGE (DWRWS & 2275ZWC)	Each relay can also be turned on and off individually to determine
	whether or not the board and component are operating. If a board is

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