Sub-Zero error code · 50 U 80
Sub-Zero Code 50 U 80: Water Flow Meter Not Detected
Sub-Zero code 50 U 80 means the water flow meter is not detected. Check power and wiring to the flow meter; replace the flow meter assembly if those are good.
Sub-Zero code 50 U 80 means the control board cannot detect the water flow meter. First verify power and wiring to the flow meter assembly, and if those check out, replace the flow meter assembly.
What 50 U 80 means
This code indicates the board sees no signal at all from the water flow meter, the sensor that measures dispensed water volume. The control expects a flow meter to report in and finds it absent, which usually means a wiring or power problem or a failed meter. Without the meter, the dispenser cannot accurately measure or limit water delivery.
Severity:Service recommended
Why 50 U 80 happens
The most common causes are a disconnected or damaged flow meter harness, a loose connector, or loss of power to the assembly. The flow meter itself can fail electrically so it no longer communicates. Corrosion or water intrusion at the connector and wiring disturbed during prior service can also break the signal.
Common causes
- Disconnected or loose flow meter connector
- Damaged or broken flow meter wiring harness
- Loss of power to the flow meter assembly
- Failed flow meter assembly (no signal)
- Corrosion or water intrusion at the connector
What you'll typically see
- Water dispenser does not work or stops dispensing
- Service mode shows code 50 U 80
- Dispensed-water functions behave erratically
- Ice fill behavior may be affected if flow is monitored
- No flow meter feedback during a dispense attempt
Parts involved in 50 U 80
- Water flow meter assembly — Replace when power and wiring are confirmed good but no signal is detected
- Flow meter wiring harness or connector — Replace or repair if the loss of signal is in the wiring
What you can check yourself
- Note the exact code shown in service mode
- Power-cycle the unit at the breaker for two minutes and recheck
- Confirm the household water supply to the unit is on
- Avoid opening dispenser or flow meter assemblies yourself
When to book a pro
Verifying power and wiring to the flow meter and confirming the assembly has failed requires metering and access behind the dispenser, which a technician should perform.
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Frequently asked
50 U 80 FAQ
What does Sub-Zero code 50 U 80 mean?
Code 50 U 80 means the control board cannot detect the water flow meter at all, the sensor that measures how much water the dispenser delivers. The board expects the meter to report in and finds it completely absent. That usually signals a disconnected or damaged flow meter harness, lost power to the assembly, or a flow meter that has failed electrically.
Can I troubleshoot code 50 U 80 myself?
Your safe steps are noting the code, power-cycling at the breaker for two minutes, and confirming the household water supply to the unit is on. Beyond that, do not open the dispenser or flow meter assemblies, because verifying power and wiring to the meter takes metering and access behind the dispenser. That part is technician work.
How do I clear code 50 U 80?
Once the meter is communicating again, after the harness, connector, or assembly is repaired or replaced, the board detects it and 50 U 80 clears. A breaker power-cycle of about two minutes refreshes the reading after the fix. If the code persists, the meter still is not reporting in and the wiring or assembly needs further attention.
Is it safe to keep using my Sub-Zero with code 50 U 80?
Cooling and food safety are not affected, but the water dispenser cannot accurately measure or limit water delivery, so it may stop dispensing or behave erratically, and ice fill can be affected if flow is monitored. It is a medium-severity code worth addressing soon so you regain reliable dispensing, but it is not a food-safety emergency.
Which part does 50 U 80 involve and what does the repair cost?
It involves the water flow meter assembly or its wiring harness and connector. If power and wiring check out but no signal is detected, the meter assembly is replaced; if the loss is in the wiring, the harness or connector is repaired. Our diagnostic is a flat $89, repairs carry a 365-day warranty, and you can book at (650) 668-1554.
How is 50 U 80 different from the low-flow and no-flow codes 50 U 86 and 50 U 87?
50 U 80 means the board sees no flow meter at all, an electrical detection problem, usually wiring or a failed meter. By contrast, 50 U 86 means the meter is present and working but reports low flow, and 50 U 87 means the meter is present but reports no flow, both pointing to the water supply or plumbing. So 50 U 80 is about the sensor being missing, not about the water itself.
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