Samsung Refrigerator F20 Error Code Fix Guide

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What This Error Means

F20 on a Samsung refrigerator means a freezer temperature sensor / defrost circuit fault.

The control board thinks the freezer temp reading is wrong or the freezer isn’t cooling/defrosting the way it should, usually from a bad sensor, bad wiring, or coils buried in ice.

  • Freezer too warm or swinging hot/cold.
  • Thick frost or a solid ice slab on the back wall of the freezer.
  • Fan noises, clicking, or the fridge running nonstop.
  • Display beeping and flashing F20 that won’t clear.

The board is basically saying: the freezer temp circuit can’t be trusted, so it throws F20.

Official Fix

This is the by-the-book route Samsung wants you to take.

  • 1. Power reset the control
    • Unplug the fridge or flip the breaker off.
    • Wait at least 5 minutes.
    • Power it back up and give it 5–10 minutes.
    • If F20 vanishes and doesn’t come back, you caught a control glitch. If it returns, move on.
  • 2. Check the freezer wall for ice buildup
    • Open the freezer and look at the back inside panel.
    • Thick “snow”, ice sheet, or bulging panel = defrost or sensor problem.
    • Panel clean but freezer warm = sensor lying or wiring issue.
  • 3. Factory-approved manual defrost
    • Move food to another fridge/cooler. Don’t skip this unless you like mushy food.
    • Unplug the fridge.
    • Leave doors open for 24 hours with towels under the unit.
    • This melts ice off the coils, fan, and sensor the slow, safe way.
    • Plug back in and let it run several hours.
    • If temps are normal and F20 is gone, you had an ice-choke problem, not (yet) bad hardware.
  • 4. Inspect / replace the freezer temperature sensor (thermistor)
    • Kill power. Unplug the fridge or flip the breaker. No guessing here.
    • Pull out freezer drawers and shelves.
    • Remove the screws and clips holding the rear freezer panel. Pry gently; it’s plastic.
    • Behind that panel you’ll see the evaporator coils and fan. Find the small bullet-shaped sensor clipped to tubing or the panel, with two thin wires.
    • If it’s cracked, swollen, corroded, or dangling loose, replace it with the proper Samsung freezer thermistor for your model.
    • Reclip the new sensor where the old one was so it “sees” coil temperature correctly.
  • 5. Check wiring and connectors to the board
    • Follow the sensor wires to their connector. Make sure it’s fully seated.
    • Look for burned pins, green corrosion, or chewed/broken wires.
    • Any melted or broken section needs repair or a new harness, not tape and hope.
  • 6. Main control board (only after sensor and wiring)
    • If the new sensor ohms out correctly and wiring is clean but F20 keeps coming back, the board may not be reading the sensor.
    • Locate the main control board (usually on the back, behind a metal or plastic cover).
    • Match the full part number on the label and replace it with the correct Samsung board for your exact model.

That’s the official ladder: reset, defrost, sensor, wiring, then board.

The Technician’s Trick

Here’s the stuff working techs use when they don’t want to babysit a 24-hour defrost.

  • 1. Forced defrost instead of a full-day thaw
    • On many Samsung French-door models, press and hold Power Freeze + Power Cool together for about 8–10 seconds until the panel beeps or changes.
    • You’re now in test mode. Tap the same button pair (or the fridge button) until you see something like Fd (forced defrost) on the display.
    • Let it run. You’ll hear sizzling and dripping as the heater cooks ice off the coils and sensor.
    • Throw towels in and under the freezer; you’ll get melt water.
    • When it exits and restarts cooling, see if F20 is gone. If it stays gone and temps are good, the root cause was ice, not bad parts.
    • If your panel doesn’t respond to that combo, skip this and stick to manual defrost.
  • 2. Connector “scrub” for flaky readings
    • With power off, unplug the sensor connector and plug it back in a few times.
    • Do the same on the control board side for that harness if you can access it.
    • This scrubs light oxidation off the pins. A dirty connector can fake a bad sensor and throw F20.
    • If the code disappears after this and stays gone, you fixed a connection issue, not a component.

If forced defrost only buys you a few days before F20 comes back, stop playing whack-a-mole. Replace the sensor or board.

Is It Worth Fixing? (The Financial Verdict)

  • ✅ Fix: Fridge under ~10 years old, cooling still decent, F20 is recent, and you’re likely in for just a sensor or fan (usually under $150 in parts).
  • ⚠️ Debatable: Unit is 10–12 years old, has a history of icing up, and you’re looking at both sensor and main board or repeated service calls.
  • ❌ Replace: Over 12 years old, plus compressor/sealed-system issues, cabinet rust, or a repair quote over half the price of a similar new fridge.

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