Error 3–3, also shown as F3E3, points to a problem with the dishwasher’s OWI module (Optical Water Indicator) and its built-in thermistor. This combined sensor reads water clarity (turbidity) and temperature so the control can decide how long to wash, when to heat, and how much to rinse. When the control detects an out-of-range reading or a failed calibration from this module, it stops trusting the data and throws F3E3.
What You’ll Notice in the Cycle
You may see longer-than-normal wash times, poor cleaning, or cycles that abort early with the code displayed. Some models start, drain, and refill several times while “hunting” for valid readings, then fault out. Others complete but leave residue because the machine never gets a clean turbidity or stable temperature signal.
Why It Happens
Two broad issues trigger F3E3. The first is sensor contamination or bad water conditions during the required self-calibration: a film of detergent on the OWI lens, food oils coating the sump, heavy suds, or very dirty initial fill can distort readings. The second is electrical or component faults: a loose or oxidized connector at the OWI, a damaged harness, a failing thermistor inside the module, or a control board that can’t read the sensor correctly. In some models, a heater that never warms the water also derails calibration because the control expects a predictable temperature rise.
Quick Safety and Setup
Switch the dishwasher off at the breaker or unplug it before you open toe-kick panels or handle connectors. Note the exact model and when the error appears—right after fill, mid-wash, or during heating—because timing helps separate calibration issues from outright sensor failures.
Clean, Reseat, and Recalibrate
Start with the sump area. Remove standing debris, wipe the OWI window clean (it’s a small, clear lens in the sump wall), and clear any greasy film around the intake screen and filter assembly. Reassemble, then reseat the OWI connector and the harness plug at the control so the locking tabs click firmly into place. Restore power and run a controlled test: many models accept a Service Diagnostics sequence that forces an OWI reset and calibration; if you don’t have the service sheet, an empty Normal or Quick cycle with fresh water (no detergent) often allows the control to recalibrate on its own. If the heater operates properly, you should see the cycle proceed without a fault as the sensor learns baseline clarity and temperature response.
When the Problem Is Hardware
If F3E3 returns immediately after a careful clean and a proper recalibration attempt, the OWI module itself often sits at fault. Internal thermistors can drift open or short and the optical channel can fail, which the control reads as bad data even in clean water. Less commonly, the wiring harness between OWI and control develops an intermittent break that opens as the tub vibrates; a gentle wiggle test on the powered-off harness can expose a weak crimp or broken conductor. Only after a known-good OWI and harness still trigger F3E3 should you consider the main control as the culprit.
Verify the Fix
After cleaning, reseating, or part replacement, run a full cycle with clear water first and then a normal, loaded cycle using fresh detergent. Watch for stable progress through wash and heat, no sudden drains or refills, and clean dishes at the end. If your model logs stored faults, clear them and confirm that F3E3 does not return on the next run.
Keep the Code from Coming Back
Rinse heavy food soils before loading, use the correct dose of high-quality dishwasher detergent, and run a monthly maintenance cycle to strip oils that fog the OWI lens. Keep filters clean and ensure the heater actually raises temperature during wash—consistent heating improves both cleaning and the sensor’s calibration stability. These simple habits protect the OWI/thermistor’s readings and prevent another F3E3.