• Water Dispense Switch/Water Dispense Sensor
a) Push Button Model: The water dispense button and DispWV are not associated with
CB. Engage the water dispense button, then check for 24VAC at DispWV. If 24VAC is present and no water is dispensed, check for water supply line shut-off valve closed, clogged water filters, clogged WV screen. If the water supply is good, replace DispWV. If 24VAC is not present, check water dispense switch continuity and CT 24VAC fuse, 125VAC power supply, and continuity.
b) Opti-Serve Model: Before engaging the water dispense Opti-Serve sensor, check for 5VDC from the locations given in the table below. If VDC is different than in the table, replace CB. If 5VDC is present, engage the Opti-Serve sensor and confirm that VDC matches the table below. If not, see "IV.F.3c. Water Dispense" to rule out a faulty Opti-Serve sensor. If the Opti‑Serve sensor checks out, replace CB. If VDC matches the table below when the Opti-Serve sensor is engaged, check for 24VAC between CB K2 connector pin #8 (DBU wire) to a neutral (LBU wire) with the Opti‑Serve sensor engaged. If 24VAC is not present, replace CB. If 24VAC is present and no water is dispensed, check for water supply line shut-off valve closed, clogged water filters, clogged WV screen. If the water supply is good, replace DispWV.
Control Board Connector | To | Control Board DC Ground | Disengaged | Engaged |
K5 Pin #7 (R wire) | | | 0VDC | 0VDC |
K5 Pin #8 (W wire) | To | K3 Pin #1 (open) | 5VDC | 0VDC |
K5 Pin #9 (BK wire) | | | 5VDC | 5VDC |
5) Fill Cycle – CB directs 24VAC power supply to WV from CB K2 connector pin #7 (R wire) to CB K3 connector pin #3 (DBU wire). Confirm 24VAC between
CB K2 connector pin #7 (R wire) and pin #8 (LBU wire). Next, confirm 24VAC between CB K3 connector pin #3 (DBU wire) and CB K2 connector pin #8 (LBU) wire. If 24VAC is present between CB K2 connector pin #7 (R wire) and #8 (LBU wire), but not between CB K3 connector pin #3 (DBU wire) and CB K2 connector pin #8 (LBU wire), replace CB. If 24VAC is present between CB K3 connector pin #3 (DBU wire) and CB K2 connector pin #8 (LBU wire) and fill cycle does not start, see "IV.B.8) Fill Cycle."
6)Ice Purge Cycle – "GM" LED is on: UF/S closes, WCR relay terminal #6 (LBU wire) and #4 (O wire) close. CB K1 connector COM (BR wire) and CB K1 connector NO (DBU wire) contacts close, energizing GM and GMPR. 60-sec. ice purge timer starts. Check for 115VAC at CB K1 connector NO (DBU wire) to a neutral (W wire). If 115VAC is not present, confirm continuity between CB connector K4 pin #3 (GY wire) and #4 (V wire). Next, confirm 115VAC at CB K1 connector COM (BR wire) to a neutral (W wire). If 115VAC is present at CB K1 connector COM (BR wire) but not on NO (DBU wire), and CB K4 connector pin #3 (GY wire) and #4 (V wire) are closed, replace CB.
7)Freeze Cycle – "GM" and "COMP" LEDs are on: 60-sec. ice purge timer terminates. CB X2 relay energizes, closing X2 relay contacts (BR and LBU wires). Confirm continuity between CB K2 connector pin #1 (DBU wire) and #2 (BR wire). After being closed for 60 seconds, confirm 115VAC between X2 (BR wire) and a neutral (W wire). Next, check for 115VAC between CB X2 (LBU wire) and a neutral (W wire). If 115VAC is present on CB X2 (BR wire), but not on CB X2 (LBU wire) and CB K2 connector pin #1 (DBU wire) and #2 (BR wire) are closed, replace CB.
