Fixing a dehumidifier that’s not detecting humidity changes

If your dehumidifier isn’t picking up on humidity changes, you’re likely left dealing with constant dampness and the risk of mold setting up shop in your home. Wanna fix it yourself? First, it’s good to get a handle on how the system works and what could be going wrong. Let’s dig into how you can figure out and sort out issues with humidity detection.

The info here might not be spot-on for your specific dehumidifier model. We aim to give useful DIY repair advice, but different models can have their own quirks, different troubleshooting steps, error codes, parts, you name it. For the best advice, check out the manual for your exact model or give us a shout if you’ve got questions.

Why your dehumidifier isn’t detecting humidity changes

Your dehumidifier uses a built-in humidity sensor to keep tabs on the moisture in the air. This little gadget sends signals to the control board, telling it when to kick the compressor and fan on or off based on the humidity level you’ve set. If the sensor’s acting up or isn’t calibrated right, your dehumidifier might run nonstop, not turn on at all, or just ignore the humidity in the room. You might still feel that stubborn mustiness even though the unit says it’s working fine.

Issues with faulty sensors or calibration can pop up because of:

• Dust and gunk clogging up the sensor parts
• Corrosion or damage from being exposed to too much moisture
• Loose wires or connectors
• Regular wear and tear over time
• Super humid or extreme temperature conditions

If you notice your dehumidifier running endlessly without making things any drier, or if it shuts off too soon, it’s a good idea to check out the humidity sensor first. Make sure it’s talking to the main control board like it should.

Signs your humidity sensor might be faulty or needs calibration

Sometimes it’s pretty clear when the sensor or its calibration is off, but other times it’s more sneaky. Here are some common red flags:

• The dehumidifier keeps running, but the humidity level doesn’t budge.
• The unit won’t turn on, even when it’s obviously humid.
• The control panel suddenly shows wild humidity readings (like jumping from 30% to 70%) for no apparent reason.
• There’s a lingering musty smell, meaning moisture isn’t being dealt with.
• The dehumidifier runs constantly but doesn’t seem to adjust based on your settings.

Before you start worrying about bigger mechanical or electrical problems, check out the sensor and its calibration. Sometimes, a quick fix there can solve these annoying humidity issues.

How to check and test the humidity sensor

Inside your dehumidifier, you’ll usually find a small circuit board or electronic part near the front air intake or around the control board area. The humidity sensor is often placed where air flows over it for accurate readings. Here’s what to do:

1. Find the sensor: Look for a small plastic or metal piece connected by a couple of wires. Its exact spot and look can vary by model, so if you’ve got a repair manual, now’s the time to use it. If not, our repair help resources might come in handy.
2. Look for obvious damage: Check for any discoloration, broken connections, or signs of rust. If it looks beat up, it might need replacing.
3. Check the wiring and connectors: Make sure the wires are snugly connected to the control board. Look out for any bent pins or loose housings.
4. Use a multimeter if needed: Some sensors can be tested with a basic resistance check. If you have your model’s wiring diagram or specs, you can test the sensor’s resistance. Set your multimeter to measure ohms, and see what you get. A bad sensor might show infinite resistance or readings that jump all over the place. If you’re not sure what numbers you’re looking for, compare it to a working sensor or check the part’s info.

If the sensor doesn’t pass these tests, it’s probably time for a new one. If it seems okay, the problem might be somewhere else. But even if the sensor looks fine, sometimes the calibration can be off.

How to replace a faulty humidity sensor

Swapping out the sensor on most dehumidifiers is pretty straightforward. You’ll need the exact part number for your unit, so use that model number when you’re ordering a new sensor from a trusted place. You can head over to AppliancePartsPros.com to find the right part. Here’s how to do it:

1. Grab your tools: You’ll need a small screwdriver (Phillips or flat-head, depending), maybe some needle-nose pliers for the wires, and your new sensor.
2. Make sure the power’s off: Double-check that the dehumidifier is unplugged. Don’t just rely on the “off” switch, unplug it completely.
3. Remove the cover and find the sensor: Use your model’s diagram or the steps above to locate it. Pay attention to how it’s positioned so you can put the new one in the same way.
4. Disconnect the old sensor: Gently undo any connectors or screws. If there’s a wire harness, you might want to label the connectors so you don’t mix them up later.
5. Install the new sensor: Attach it just like the old one was. Make sure everything’s snug and secure.
6. Put it all back together and test it: Replace any covers, plug it back in, and give it a test run. Set your desired humidity level and see if it behaves, turning on and off when it’s supposed to.

This simple swap often gets your dehumidifier working like new. Keep an eye on it in a room with known humidity levels to make sure everything’s back on track.

How to recalibrate the humidity sensor

Some dehumidifiers let you recalibrate the sensor, bringing its readings in line with the actual humidity. If you think the sensor’s a bit off, reading too high or too low, a quick calibration might do the trick. Here’s how you might go about it:

1. Get a reliable hygrometer: Place a trusted humidity meter nearby to get an accurate reading of the room’s humidity.
2. Check your manual or control board: Depending on your unit, there might be a small adjustment dial (a potentiometer) on the control board or a calibration mode you can access through the controls.
3. Make adjustments: If there’s a dial, tweak it slightly and see how the dehumidifier’s reading changes. If it’s menu-based, follow the on-screen instructions to align it with your hygrometer’s reading.
4. Wait a bit: Give it a few minutes after each tweak to see if the readings settle correctly.
5. Compare readings again: If your dehumidifier’s display is within a couple of percentage points of the actual humidity, you’re good to go. A tiny difference is usually no biggie.

Calibration steps can vary a lot between different brands and models. Always check any paperwork that came with your dehumidifier or look up repair help for your specific part. If there’s no way to calibrate it yourself and the readings are still off, you might need to replace the sensor after all.

Wrapping up and more resources

Always make sure you’ve got the right model number before ordering or installing parts. If you’re not 100% sure, check out our guide on how to find your appliance’s model number. Getting the exact info helps ensure the replacement sensor is the perfect fit.

If you’re still having trouble or need more help, swing by our repair help section for more articles, tutorials, and tips tailored to your appliance. Whether you’re dealing with error codes or more complex parts, AppliancePartsPros.com has a ton of info you can dig into whenever you like.

We’ve got a huge selection of parts at AppliancePartsPros.com to get your dehumidifier back in tip-top shape. Don’t forget to follow us on Facebook and on Twitter at for more repair tips, updates, and special deals.