Sub Zero Refrigerator Water Dispenser Not Working – How to fix? by ApplianceRepairLosAngeles.net

The part(s) or condition(s) listed below for the symptom Refrigerator not cooling are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.

Most Frequent Causes for Refrigerator Water Dispenser Not Working

Cause 1 Water Tube in Door is Frozen
To determine if the water supply tube is frozen, disconnect the tube at the bottom of the door and blow air through it. If air does not pass through, this indicates that the water supply tube is frozen. If the water supply tube is frozen, thaw it out. In addition, ensure that the freezer is kept at the proper temperature. The freezer temperature should be kept from 0-10 degrees Fahrenheit. If the freezer is too cold, the water line may freeze.
Cause 2 Water Inlet Valve
The water inlet valve opens to supply water to the dispenser. If the water inlet valve is defective, or if the water pressure is too low, the water valve will not open. The valve requires at least 20psi to function properly. Make sure that the water pressure to the valve is at least 20 psi. If the water pressure is sufficient, use a multimeter to test the water inlet valve for continuity. If the water inlet valve does not have continuity, replace it.
Cause 3 Low Water Pressure from House Supply
The home may have insufficient water pressure. The water inlet valve supplies water to the water dispenser. The water inlet valve requires a minimum of 20 psi to function properly. Check the water flow and test the pressure to determine if it is at least 20 psi.
Cause 4 Dispenser Control Board
The dispenser control board governs most of the functions of the dispenser system. If the control board is faulty, it may stop supplying power to the entire dispenser system. If only one dispenser part is not working, test each of the dispenser components before testing the control board. It is more likely that a single part has failed. If the entire dispenser system is not working, the control board is more likely to be at fault.
Cause 5 Dispenser Switch
The dispenser switches send voltage to the dispenser. If one of the dispenser switches is defective, the dispenser will not work. To determine if a dispenser switch is defective, use a multimeter to test each switch for continuity. If a dispenser switch does not have continuity, replace it.
Cause 6 Water Filter
A clogged water filter can restrict the flow of water to the dispenser and prevent the dispenser from working properly. The water filter should be replaced about every six months to maintain proper water flow and ensure water quality.
Cause 7 Door Switch
The door switch turns off the ice and water dispenser when the refrigerator door is open. If the door switch fails, the dispenser will not turn on. To determine if the door switch is defective, use a multimeter to test it for continuity. If the door switch does not have continuity when activated, replace it.