F5 GE microwave error: How to troubleshoot & fix

Get ready to decode that freaky F5 error flashing on your GE microwave with this troubleshooting guide. This code can strike some GE microwave models if there’s a problem with the humidity sensor or, in rarer cases, the control board.

If you find out that you need any replacement parts for your GE microwave, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

Let’s tap into your inner technician to get your machine working again.

Disclaimer: The error code information provided in this article is based on general service manuals and may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

What causes an F5 error?

The F5 error code usually means there’s a problem with the humidity sensor inside the microwave oven. Specifically, it means the control board is detecting a short circuit condition in the humidity sensor or its wiring during a cooking cycle.

The humidity sensor monitors the steam and humidity levels inside the microwave cavity as food cooks. A short circuit in this sensor or the attached wires while the microwave is running can trigger the F5 error, which will prevent the microwave from cooking.

Where is the humidity sensor?

You can find the humidity sensor mounted directly on the generator assembly inside the microwave. The generator produces the microwave energy that cooks the food.

The humidity sensor is a small plastic cylinder or metal housing that protrudes into the oven cavity to detect the interior humidity. It connects back to the main control board via an electrical wiring harness.

Microwave safety precautions

Microwaves contain high-voltage parts and can store voltage even when they’re disconnected from a power source. Please be very careful while working on a microwave’s internal parts to avoid electrocution, which has the potential to cause serious injuries or death.

• Always unplug the microwave before troubleshooting or making repairs.
• Discharge the high-voltage capacitor before working on high-voltage parts to eliminate the risk of electric shock.
• Never attempt to run the microwave while its casing is open or when internal parts are exposed. Always completely reassemble the microwave before testing or using it.
• Never attempt to bypass any microwave safety features.
• With the microwave unplugged, remove the outer case to gain internal access.
• Wear insulating gloves and use insulated tools when testing any parts.
• Check all parts for damage before reassembling and powering up the microwave again.

More safety tips

• Always power off and unplug your appliance or switch off the circuit breaker before you attempt any maintenance or replacement work. This keeps you safe by preventing any risk of electric shock.
• If the appliance has recently been used, give it plenty of time to cool down before working on it.
• Take your time while working to prevent accidents and personal injuries. Rushing is the enemy of precision.
• Work in a well-lit area so you can clearly see and access appliance parts.
• Keep your workspace free of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with wet hands. Make sure the work area is completely dry.
• Check the user manual to see if there are specific installation or safety instructions related to your appliance or replacement part.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause personal injury.
• Wear insulated work gloves to protect your hands from sharp metal parts and debris.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Don’t test live voltage with a multimeter if you’re unfamiliar with how to prevent short-circuiting.

Read more: 10 reasons why a microwave won’t heat

How to troubleshoot an F5 error

1. Inspect the humidity sensor

1. Turn off the microwave and unplug it from the outlet.
2. Remove the exterior panels.
3. Find the humidity sensor that’s mounted on the microwave generator housing.
4. Closely look over the plastic cylinder or metal sensor housing and pins for any cracks, burns, or physical damage. If you find any damage, you’ll need to replace it.
5. Make sure the sensor is firmly seated in the generator housing.
6. Check that the wiring harness connected to the sensor doesn’t have any fraying, chafing damage, or detached leads. If you see any damage, replace the wiring harness.

If the sensor, housing, and wiring harness look good, you can move on to the next step.

2. Check the humidity sensor

1. Make sure all wires are connected and the microwave is plugged in for 9 minutes.
2. Press and hold buttons 7 and 8 at the same time.
3. Check the diagnostic number in the display. If the reading is less than 6 and the sensor and harness aren’t damaged, the most likely issue would be the main control. Move to the next step to verify if that’s the problem.

Read more: How To Use A Multimeter To Check Appliance Parts

3. Isolate the humidity sensor

1. Make sure the microwave is turned off and unplugged.
2. Find where the humidity sensor wires end at the control board connector.
3. Detach the sensor wires from the control board pins.
4. Restore power to the microwave without the sensor connected and see if the F5 error code remains or disappears. This tests whether the short is on the control board or in the external sensor circuit.

If the F5 error disappears, then the short is in the sensor circuit, and the humidity sensor should be replaced.

If the F5 error still shows up with the humidity sensor disconnected, then you should replace the microwave’s control board.

4. Test the microwave

1. After making any repairs, reassemble the microwave and plug it back in.
2. Run a short cooking cycle with a small bowl of food or water to make sure the F5 error code doesn’t return.

Read more: How to Clean a Microwave

More information

Thank you for reading! We hope this guide helped you get your microwave working again.

If you have any other appliance repair needs or projects, don’t hesitate to explore our thousands of free videos and troubleshooting guides available. If you need replacement parts or some extra help, grab your model number and head over to AppliancePartsPros.com, where you can chat with a pro, order parts, read our DIY blog, and more. We can also help you troubleshoot common microwave problems here.

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