Sub-Zero · Refrigerator error code

40 9 40Dispenser excessive run time

Cross-checked Power off, standard tools

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Related diagnostic guides

Guide · Refrigerator

Water dispenser slow or weak flow

Work from the filter outward: filter, supply flow at the fridge, then the fridge's inlet valve and lines. Freezing in the door line is another cause.

5 steps ~40 mineasy

Guide · Refrigerator

Water dispenser not working (ice maker may still work)

If ice is still being made, the water supply reaches the valve, so the fault is usually a frozen door line, the dispenser-side valve coil, the dispenser switch or a lock mode. Isolate the problem by section.

5 steps ~40 mineasy

Install · Refrigerator

Refrigerator water line and ice maker hookup

Run a 1/4 in supply (copper or a PEX kit made for refrigerators) from an accessible shutoff to the fridge inlet, leave a service loop so the fridge can be pulled out, flush the line before connecting and flush the new filter afterward. Avoid self-piercing saddle valves where code or the manufacturer discourages them.

6 steps ~60 mineasy

More Sub-Zero refrigerator codes

Sub-Zero · Refrigerator

10 1 02

Zone 1 cabinet thermistor unstable

Cross-checked High-voltage / caution

Sub-Zero · Refrigerator

10 2 00

Freezer cabinet thermistor open

Cross-checked

Sub-Zero · Refrigerator

10 2 01

Freezer cabinet thermistor shorted

Cross-checked

Sub-Zero · Refrigerator

10 7 00

Ambient (on control board) thermistor open

Cross-checked

Sub-Zero · Refrigerator

10 7 01

Ambient (on control board) thermistor shorted

Cross-checked

Sub-Zero · Refrigerator

10 7 02

Ambient (on control board) thermistor unstable

Cross-checked