Sub-Zero 600 and 700 Series Code 08: Freezer coil thermistor reading bad

What 08 means

When a legacy 600 Series unit like the 650/F, or a 700 Series model such as the 736TCI, shows code 08, the freezer evaporator thermistor has been open or shorted for 10 seconds or more, or its readings are erratic. This sensor sits near the freezer coil and tracks its temperature. Without it, the coil can ice up, airflow drops, and the freezer may go through warm periods.

Common causes of 08

Freezer evaporator thermistor open or shorted
Damaged wiring near the freezer coil
Loose connection at the board

✓ One safe check you can try

1. Note code 08. 2. Look for frost on the freezer back wall or around the vents. 3. Power the unit down at the breaker and restore it two minutes later. 4. Keep the freezer closed and watch its temperature with a thermometer. 5. Get in touch if the display shows it again.

! Why to stop there

The sensor is behind the freezer evaporator cover.
Testing needs a meter and reference values.
Ice on the coil must be melted safely.

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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Other Refrigerator codes

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0808 questions

Why is my freezer frosting up with code 08?

The control uses the coil sensor to manage the freezer evaporator. When that reading is lost, frost can keep building on the coil until it chokes off airflow into the freezer.

Should I treat 08 like 07?

07 is the freezer cabinet sensor measuring the air, while 08 is the freezer coil sensor. Owners often see frost with 08 and drifting temperatures with 07.

What does it cost?

We test the sensor and wiring, clear any ice and then give you a written price for the part. Our workmanship on the repair is covered for 30 days.