Error code · Range

LG Range Codes F4, F5: Lower Oven Temperature Probe

On LG electric and gas ranges with a numeric F-code display, F4 and F5 are listed as a lower oven thermistor error. The thermistor is the temperature probe that reports how hot the lower oven is.…

Medium · inspection needed

(713) 597-5662

Code: F4, F5
Appliance: Range
Brand: LG
Warranty: 30-day workmanship

What F4, F5 means

On LG electric and gas ranges with a numeric F-code display, F4 and F5 are listed as a lower oven thermistor error. The thermistor is the temperature probe that reports how hot the lower oven is. If the reading is lost or out of range, the control stops heating that oven and shows the code. The list says only lower oven, so we do not assume every range has one.

Common causes of F4, F5

The lower oven thermistor reading out of range
A wire or connector at the probe that is loose
A control that is not reading the probe
A probe that has stopped responding

✓ One safe check you can try

1. Press CLEAR/OFF and attempt the oven function again. 2. If F4 or F5 returns, turn the circuit breaker off for 30 seconds and back on. 3. If it appears after that, stop using the lower oven and call us. 4. Do not open the lower oven rear panel to look at the probe yourself.

! Why to stop there

F4 and F5 share a label, so we test the circuit to see which reading each number reports.
We compare the probe against a known temperature before replacing it.

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 Range codes

F19LG Range Code F19: Oven Not Heating F20LG Range Code F20: Lower Oven Door Lock F21, F22, F24, F25LG Range Codes F21, F22, F24, F25: Steam Sensors F27LG Range Code F27: Cooling Fan During Self Clean F3LG Range Code F3: Touch Pad Keys F36LG Range Code F36: Transistor F38LG Range Code F38: Main Board and Inverter F42LG Range Code F42: Supply Voltage

F4, F5F4, F5 questions

Are F4 and F5 different?

They are two entries for a lower oven thermistor error. We test the probe circuit to see what each reading means. We do not assume every range has a lower oven, so we check yours.

Can I use the upper oven?

If your range has one and the code names the lower oven, the upper may work. We check before you rely on it. Do not rely on that oven if it will not heat.

Will clearing the code help?

CLEAR/OFF and a breaker reset can clear a one-time reading from the probe. If it repeats after that, we test the probe and its wiring before replacing anything.

Book a visit

Still seeing F4, F5?

A technician diagnoses it on site and gives you the price in writing before any work starts.

(713) 597-5662