What does F4 mean on a GE microwave?

The humidity sensor that sensor cooking reads is not answering the control. Sensor cycles refuse to run; timed cooking still works. F4 that returns is the humidity sensor behind the cavity vent — a part, a technician's job, and on a machine under warranty a warranty call.

What does SENSOR ERROR mean on a GE microwave?

Not a fault in the machine. A sensor cycle was started and the sensor never got its reading — the door was opened early, the cavity was already steamy or hot from the last run, or the vent was covered. Press Clear/Off and run the sensor cycle again with the door shut. Every sensor cycle failing on a cool, dry cavity with the door shut is the humidity sensor — a part, and F4 usually joins it.

What does FAN ON mean on a GE microwave?

Not a fault. The vent fan turned itself on because the air coming up from the cooktop below got hot — a boiling pot, a burner on high. It protects the microwave and cannot be turned off until the heat is gone. Nothing to fix; wait. A fan that comes on by itself with the cooktop cold, and keeps running, has a thermostat on the microwave's underside that is reading wrong — a part.

Error codes · GE · Microwaves

GE microwave error codes: two F codes, a sensor message and a fan that turns itself on.

A GE over-the-range microwave prints an F code only for a stuck keypad or its humidity sensor, and the words people call about most — SENSOR ERROR and FAN ON — are not faults. The control lock is the other one. The four badges — GE, GE Profile, Café and Hotpoint — run one control, so the words read the same. Find what yours is showing below; a microwave that hums and does not heat prints nothing at all, and that one is a service call for a reason the strip above gives.

Covers: 2015-and-newer over-the-range microwaves (JVM3160, JVM6175, JVM7195, JNM3163, PVM9005, PVM9179, PVM9225, CVM517, CVM721, Hotpoint RVM5160) under the GE, GE Profile, Café and Hotpoint badges, on one control.

Jump to the codes Text (573) 353-8511

Jump to a code · 5 on this page

The code as the display prints it; an older spelling sits under it on the card.

F3Shorted keypad

F4Humidity sensor fault

SENSOR ERRORSensor cook interrupted

FAN ONAutomatic fan

LOCControl lock on

GE · First

Before you clear it

GE prints a code on the display (E22, F7, dE); a machine with no display blinks a light pattern — count the blinks and read the manual's table.

The display prints an F code (F3, F4) or a word (SENSOR ERROR, FAN ON, LOC). A microwave that runs and does not heat prints no code — the capacitor inside holds a charge that can hurt long after the plug is pulled, so no panel comes off at home; that one is a service call.

The reset: unplug the microwave (the plug is in the cabinet above it — the cord runs up through the hole in the cabinet floor) or switch off its breaker for one full minute, plug it back in and set the clock.

A sensor-cook fault is almost always the door: the sensor needs the door shut from the moment Start is pressed until it reads the steam. Opening the door to peek is what the message means.

The model and serial plate is on the front frame of the microwave, inside the door — open the door and look at the frame on the left or at the bottom. Every warranty call starts with those two numbers.

Section 1 of 2

F codes

F3#1

Check, then call

Code

Shorted keypad

What it means

The control sees a key held down for longer than a hand would hold it. A spill, a cabinet door pressing on the panel, or the keypad's membrane shorted.

Check first

Press Clear/Off and wipe the panel dry, including the edge where the glass meets the frame.
Nothing presses on the panel — the cabinet door beside it, a magnet, a hanging utensil.
Unplug the microwave for one full minute.

The fix

F3 that returns with a clean panel and nothing touching it is the keypad — on most models the whole control panel assembly — a part, a technician's job, and on a machine under warranty a warranty call.

Stop & call

F3 after a reset with a clean panel is a service call. A microwave that beeps and shows it on its own at night is the same part — unplug it from the cabinet above until it is looked at.

F4#2

Service call

Code

Humidity sensor fault

What it means

The humidity sensor that sensor cooking reads is not answering the control. Sensor cycles refuse to run; timed cooking still works.

Check first

Unplug the microwave for one full minute, plug it back in and try a sensor cycle with the door shut the whole time.
Timed cooking (a number of minutes, then Start) still heats normally — if it does, the microwave is usable while you wait.

The fix

F4 that returns is the humidity sensor behind the cavity vent — a part, a technician's job, and on a machine under warranty a warranty call.

Stop & call

F4 after a reset is a service call. Cook by time until the sensor is replaced; nothing else is affected.

Section 2 of 2

Words that are not a fault

SENSOR ERROR#3

Fix at home

Code

Sensor cook interrupted

What it means

Not a fault in the machine. A sensor cycle was started and the sensor never got its reading — the door was opened early, the cavity was already steamy or hot from the last run, or the vent was covered.

Check first

Keep the door shut from Start until the microwave itself ends the cycle or shows the time left; a peek cancels the reading.
The cavity is cool and dry — wipe it out after a steamy run and wait a minute before the next sensor cycle.
The food is covered loosely, not sealed; the sensor reads the steam that escapes.
The vent grille along the top edge of the microwave is clear.

The fix

Press Clear/Off and run the sensor cycle again with the door shut. Every sensor cycle failing on a cool, dry cavity with the door shut is the humidity sensor — a part, and F4 usually joins it.

FAN ON#4

Fix at home

Code

Automatic fan

What it means

Not a fault. The vent fan turned itself on because the air coming up from the cooktop below got hot — a boiling pot, a burner on high. It protects the microwave and cannot be turned off until the heat is gone.

Check first

A pot is boiling or a burner is on under the microwave; the fan stops a few minutes after the cooktop cools.
The grease filters under the microwave are clean enough to see light through — a clogged filter traps the heat.

The fix

Nothing to fix; wait. A fan that comes on by itself with the cooktop cold, and keeps running, has a thermostat on the microwave's underside that is reading wrong — a part.

LOC#5

Also printed as LOCKED

Fix at home

Code

Control lock on

What it means

Not a fault. The pads are locked so a child cannot start the microwave; the display reads LOC (or LOCKED) and a press does nothing.

Check first

Press and hold Clear/Off for about three seconds (the pad with the padlock on panels that print one). The word leaves the display.

The fix

The pads answer again.

Warranty · When to file

When it's a warranty call

Every unit leaves with the manufacturer's full factory warranty. The codes below name a part inside the machine — once the checks have ruled out the install, the power and the hoses, call GE's line with the model and serial, and text us if you want a hand with the claim.

F4Humidity sensor fault

Warranty help for GE

All units are surplus inventory (open box, cancelled order, customer return, overstock, or minor scratch & dent). Every unit includes the manufacturer's full factory warranty. Please inspect thoroughly in person before purchasing — cosmetic imperfections or missing accessories are possible.

Still stuck?

Text us the model number and what it's doing — we'll point you at the next step.

A fix, a part, or a warranty call — the plate's model and serial plus one line about the symptom is all it takes to tell which.

File a warranty inquiry Text (573) 353-8511 Browse Inventory Or reach us another way

These pages are educational. Every appliance is a little different — follow the manufacturer's manual and local code, and leave gas, water heater and 240V work to a licensed installer.

All error codes GE washers GE dryers GE refrigerators GE dishwashers GE ranges & ovens GE cooktops