What 50-U-87 Means
Sub-Zero code 50-U-87 is documented on Sub-Zero's Classic and narrows the problem to a load or part-level issue — the control board expects a specific part to respond and isn't getting the expected signal back. 50-U-87 typically shows up alongside a service light or wrench flashing, and Sub-Zero’s own materials don’t specify which exact part from this page alone.
Common Causes of 50-U-87
- The load part 50-U-87 points to (compressor, fan, valve, or relay) not responding the way the control board expects
- Wiring or connector problem feeding that part
- Control board not correctly switching the part
🔧 One Safe Check You Can Try
For 50-U-87, cut power to the unit at the home circuit breaker for 30 seconds, then restore it and watch whether the code returns — this clears a real share of Sub-Zero codes without a part being involved.
⚠ Why You Shouldn't Go Further Than That
- Because 50-U-87 is read against Sub-Zero’s Classic numbering specifically, the same digits could point to a different problem on another Sub-Zero platform — confirm it against your unit’s model and serial number first.
- When the breaker reset fails to clear 50-U-87, that confirms a genuine problem instead of a one-off glitch, and it’s time to book a diagnostic visit.
- Because a likely cause behind 50-U-87 is the compressor itself, checking it means opening a panel near the sealed refrigerant system — that work goes to an EPA-certified technician who isolates power before opening anything.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.