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GE Appliances Microwave Error Code F4

Reviewed by the ApplianceErrors Editorial Team · Verified against manufacturer service documentation · Last verified: July 19, 2026
✓ Low Severity 👨‍🔧 Call a Pro

Open humidity sensor — sensor cooking disabled

The most common cause of the F4 error on a GE Appliances microwave is failed (open) humidity sensor (~60% of cases); start with: use manual modes meanwhile.

💰 DIY cost: $0–$0 👨‍🔧 Pro cost: $110–$230 Save $110+ by doing it yourself
GE Appliances Microwave error code F4 on the display panel
How the F4 code appears on a GE Appliances microwave display

What Does Error Code F4 Mean on a GE Appliances Microwave?

Open humidity sensor — sensor cooking disabled.

F4 fires when the control board reads the humidity sensor circuit as open — an infinite or out-of-range resistance rather than the varying value it expects as steam builds. Because sensor-cook programs depend on tracking rising humidity to judge doneness, the board disables or aborts those modes and posts F4. Manual time-based cooking is unaffected. This distinguishes F4 from shorted-sensor or thermistor codes and from keypad or control-board faults that lock out all functions.

Models affected: GE microwaves equipped with sensor-cook features (Popcorn, Reheat, Sensor Cook), covering over-the-range and countertop models with a humidity sensor in the vent path
What owners report: Owners commonly report F4 appearing only when they start Popcorn, Reheat, or a Sensor Cook program, while normal timed cooking works fine. A brief breaker power-reset sometimes clears a one-off glitch, but a persistent code usually points to the sensor or its connector and many people simply keep using manual modes until they schedule service.

What Causes Error Code F4?

Here are the most common causes in order of frequency. Start with the most likely cause before moving to the next:

  1. 1
    Failed (open) humidity sensor 60% of cases
  2. 2
    Connector or harness fault 25% of cases
  3. 3
    Control board input fault 15% of cases

How to Fix GE Appliances Microwave Error Code F4

👨‍🔧 Call a Pro Est. time: 1–3 hours
⚡ Safety first: Unplug the appliance before opening any panels or touching internal components.
  1. 1

    Use manual modes meanwhile

    Time-based cooking is unaffected — the fault only blocks sensor-driven modes.

  2. 2

    Power-reset

    Breaker off for 60 seconds and retry a sensor-cook mode.

  3. 3

    Book sensor replacement

    The humidity sensor mounts in the vent path inside the case.

    ⚠️ Internal access is technician-only — HV capacitor hazard.

How to Reset Error Code F4

Press Cancel/Off to clear the code. The microwave remains fully usable in manual modes while you decide on the repair.

Note: If the error returns after resetting, the underlying issue has not been resolved. Work through the fix steps above.

Did this guide fix your appliance?

When to Call a Professional

Because manual cooking still works, this is the rare microwave fault you can reasonably live with — repair it opportunistically or when convenience matters.

Average professional repair cost for this issue: $110–$230

Related Error Codes

F1
Open thermal sensor — cavity temperature not detected
⚠ Medium Severity
F3
Shorted touchpad — keypad fault
⚠ Medium Severity

Same Code on Other Brands

Error code F4 appears on these other brands too. See every brand that shows F4 →

Whirlpool logo
Whirlpool Oven F4
Shorted oven temperature sensor — sensor reading short
Kenmore logo
Kenmore Oven F4
Oven temperature sensor shorted
Miele logo
Miele Refrigerator F4
Fan motor fault

Find Replacement Parts

Use these links to find the exact replacement parts for your GE Appliances Microwave:

🔩
Search PartSelect
GE Appliances Microwave repair parts
🔧
Search RepairClinic
Step-by-step video guides

External links — ApplianceErrors.com is not affiliated with these retailers.

More GE Appliances Microwave Error Codes

F2 Shorted thermal sensor

Frequently Asked Questions

Can I keep using my GE Appliances Microwave when error F4 appears? +
Usually yes — F4 is a low-severity sensor notice that rarely stops the microwave from working, but clearing the underlying cause prevents it from escalating.
What most commonly causes F4 on a GE Appliances Microwave? +
Across reported GE Appliances microwave repairs, the most frequent is failed (open) humidity sensor (60% of cases), connector or harness fault (25%), then control board input fault (15%). Check them in that order before replacing any parts.
F4 keeps coming back after a reset — what should I check next? +
A reset only clears the stored F4 fault; if it returns, the sensor problem is still present. Move on to the physical checks — use manual modes meanwhile, then power-reset — since the code will reappear until the root cause is resolved. This is a repair most owners hand to a technician.
How much does it cost to fix GE Appliances Microwave error F4? +
A DIY repair typically runs $0–$0 in parts, versus $110–$230 for a professional service call, so handling it yourself saves around $110. Expect the work to take a full service visit.
Which GE Appliances Microwave models show error F4? +
F4 is documented on GE microwaves equipped with sensor-cook features (Popcorn, Reheat, Sensor Cook), covering over-the-range and countertop models with a humidity sensor in the vent path. Other units sharing the same control platform can display it too, so the fixes here generally transfer across the series.

Sources & References

Content verified against manufacturer service documentation. Last verified: July 19, 2026.

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