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Introduction

Does your Instant Pot show the dreaded C6 error while making sad, alarming beeps? Follow this guide to diagnose what’s wrong and learn how to fix it!

The C6, C6L, and C6H errors means that one of the pressure sensors isn’t working. Most of the time, it’s due to a buildup on the sensor contacts. Cleaning the contacts will likely fix the problem.

This guide was written with an Instant Pot DUO80, but the general procedure can be applied to many electric pressure cookers because most use similar electronics and sensors.

  1. Be sure to unplug your Instant Pot before you begin your repair. Once opened, there's exposed wiring that can electrocute you if the device is plugged in. Flip the Instant Pot upside down. Use a T15 Torx driver to remove the screw securing the bottom plate.
    • Be sure to unplug your Instant Pot before you begin your repair. Once opened, there's exposed wiring that can electrocute you if the device is plugged in.

    • Flip the Instant Pot upside down.

    • Use a T15 Torx driver to remove the screw securing the bottom plate.

    • Twist and remove the bottom plate.

    • Depending on your model, this procedure may be slightly different.

  2. Here's a quick overview of the Instant Pot pressure sensors. Depending on your model, the components may differ slightly. The T6L (low pressure) sensor and its connector. Some models may not have this.
    • Here's a quick overview of the Instant Pot pressure sensors. Depending on your model, the components may differ slightly.

    • The T6L (low pressure) sensor and its connector. Some models may not have this.

    • The T6H (high pressure) sensor and its connectors.

    • These two "pressure sensors" are actually bimetal temperature switches. The Instant Pot uses these to estimate pressure using the Ideal Gas Law.

    • Each sensor consists of metal strips. Normally, the strips touch each other, creating an electrical path.

    • Once the Instant Pot heats up, the strips heat up to the point where they flex apart, breaking the electrical circuit. The temperature they flex apart is governed by the metal they use, as well as calibration screws.

    • The screws underneath the white resin are calibration screws.

    • Don't mess with the calibration screws! They will change what temperature and pressure the Instant Pot turns off, and can result in inaccurate and dangerous cooking situations.

    • Use a spudger or your finger to firmly press the top of a sensor. You should hear a loud click, signifying that the bimetal strips in the sensor are flexing properly.

    • Repeat for the second sensor.

    • If you don't hear a click, the contacts may be fused together, or the bimetal material is worn out. If they are worn, you'll need to replace the sensor.

  3. The next three steps show how to test the high pressure sensor. You should check this sensor if you get a C6 or C6H error. If you don't have a "duo" Instant Pot, you will only have one pressure sensor, and it's this high pressure one.
    • The next three steps show how to test the high pressure sensor. You should check this sensor if you get a C6 or C6H error.

    • If you don't have a "duo" Instant Pot, you will only have one pressure sensor, and it's this high pressure one.

    • Use pliers or your fingers to lift and disconnect one of the sensor's spade connectors from the circuit board.

    • These connectors can be stubborn. Gently wiggle the connector as you pull to loosen it.

    • This disconnects the sensor electrically, so we can do a continuity test.

  4. Attach a multimeter lead to both exposed ends of the sensor wires, making sure the leads don't touch each other. Test lead polarity doesn't matter for these tests. Set your multimeter/ohmmeter to resistance mode, or continuity mode.
    • Attach a multimeter lead to both exposed ends of the sensor wires, making sure the leads don't touch each other.

    • Test lead polarity doesn't matter for these tests.

    • Set your multimeter/ohmmeter to resistance mode, or continuity mode.

    • In its resting state, the pressure sensor should be continuous, which means the meter should read almost zero resistance.

    • If the meter shows a high resistance or no continuity, it could mean that the sensor contacts are dirty. Double-check your meter contacts and make sure they're grasping onto the wires.

    • Use a spudger or your finger to firmly press on the top of the sensor until it clicks.

    • The meter should change to show no continuity (0L, in my meter's case). If it doesn't, there is a potential electrical short—the contacts may be fused, or you may need to replace the sensor.

  5. Repeat the test on the low pressure sensor if you get a C6L error. If you don't have a "duo" Instant Pot, you won't have this sensor. Disconnect the low pressure sensor by squeezing its circuit board connector to disengage the lock, then pull straight up.
    • Repeat the test on the low pressure sensor if you get a C6L error.

    • If you don't have a "duo" Instant Pot, you won't have this sensor.

    • Disconnect the low pressure sensor by squeezing its circuit board connector to disengage the lock, then pull straight up.

    • Attach a multimeter lead to both exposed ends of the sensor wires, making sure the leads don't touch each other.

    • Set the meter to resistance/continuity and test for continuity, when the sensor is resting, and when it's depressed.

  6. If your tests suggest that you may have dirty contacts, or you suspect the contacts have fused, follow the next steps to remove the sensors to clean them. Use a Phillips screwdriver to remove the screw securing the sensors to the Instant Pot.
    • If your tests suggest that you may have dirty contacts, or you suspect the contacts have fused, follow the next steps to remove the sensors to clean them.

    • Use a Phillips screwdriver to remove the screw securing the sensors to the Instant Pot.

    • This screw can be very tight, because heat from the Instant Pot transfers through it. Be sure to use the right sized screwdriver to avoid stripping it.

    • Lift the sensor assembly out of its recess.

  7. Press down on the sensor to open the contacts. Use some sandpaper, a file, or electrical contact cleaner to clean the contacts. Be sure to clean both mating surfaces. Use some sandpaper, a file, or electrical contact cleaner to clean the contacts. Be sure to clean both mating surfaces.
    • Press down on the sensor to open the contacts.

    • Use some sandpaper, a file, or electrical contact cleaner to clean the contacts. Be sure to clean both mating surfaces.

  8. Use a multimeter to test the sensors for proper operation before you reassemble your Instant Pot.
    • Use a multimeter to test the sensors for proper operation before you reassemble your Instant Pot.

Conclusion

To reassemble your device, follow these instructions in reverse order.

2 other people completed this guide.

Arthur Shi

Member since: 01/03/2018

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2 Comments

We almost had to throw some food away because the “C6 L” error in the middle of making dinner. Your instructions were clear and fixed the issue. Thanks Arthur!

Kyle P - Reply

Thanks for this helpful tutorial?

Abdul Kadir - Reply

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