Sub-Zero Classic BI Code 50-U-87: Flow meter detects no water

What 50-U-87 means

Classic BI models like the BI-36UFD/S log 50-U-87 when the water flow meter does not detect any flow at all. The control opened the water path but saw nothing pass through the meter. The first check is the water pressure to the unit, since recent pressure drops can cause this code. Ice production stops, and on dispenser models door water stops completely, while cooling continues as usual.

Common causes of 50-U-87

Water supply shut off or very low pressure
Recent pressure drop in the house
Fully clogged filter
Flow meter not reading

✓ One safe check you can try

1. Make sure the household water shutoff to the unit is fully open. 2. Check whether there has been recent plumbing work or a pressure drop. 3. Replace the water filter if it is old. 4. Turn the ice maker off and on to retry once water is restored.

! Why to stop there

Pressure and flow must be verified at the unit.
Flow meter testing needs diagnostic tools.
Water connections must be resealed properly.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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50-U-8750-U-87 questions

Why do I get no water at all?

The flow meter saw no water pass after the control opened the water path. Check that the shutoff is open and pressure is normal, since pressure drops in the house can cause 50-U-87.

How is it different from 50-U-86?

50-U-86 means water is moving but too slowly, while 50-U-87 means the flow meter detected no water at all. Both start with the same supply checks, but no flow often points to a closed or failed supply.

What will you check?

We measure pressure at the inlet, test the water valve and the flow meter, and inspect every line for a closed or crushed section. You receive a written price first, with our 30-day workmanship warranty.