How to test and replace a dehumidifier capacitor

If your dehumidifier’s acting up, maybe it won’t start or just hums without really doing anything, the capacitor might be the culprit. It’s annoying when you need it to keep the humidity in check and it’s just not cooperating. So, in this guide, we’ll walk you through spotting, testing, and swapping out a bad capacitor to get your dehumidifier back in action.

This info might not perfectly match your appliance model. We do our best to give solid DIY repair tips, but different models can have their own quirks with troubleshooting steps, error codes, parts, and so on. For spot-on advice, it’s best to check your appliance’s manual or just reach out to us if you’ve got questions.

Understand the importance of the dehumidifier capacitor

So, the capacitor in your dehumidifier? It’s that small, cylinder or oval thing that controls the electrical current to the compressor or motor. Basically, it gives the compressor or fan motor that initial kick to get going. Without a functioning capacitor, your dehumidifier might struggle to turn on or keep running. If the capacitor’s shot, you might hear rattling, humming, or it might just give you the silent treatment when you hit the power button.

Signs of a faulty dehumidifier capacitor

Oftentimes, you might not suspect the capacitor’s acting up until the dehumidifier won’t start. But there are a few hints you can look out for:

• The fan or compressor doesn’t kick in, even though it’s plugged in.
• You hear a humming noise, but nothing else happens.
• It starts and stops randomly, or just can’t keep going smoothly.
• You spot a bulge, swelling, or maybe some leakage from the capacitor itself.

Tools you need for testing and replacing the capacitor

Before diving in, make sure you’ve got the right tools and stuff to safely check and swap out the capacitor. You’ll need:

• Screwdriver set 
• Multimeter 
• Insulated pliers 
• Protective gloves and safety glasses 
• New capacitor: It should match the original’s capacitance and voltage ratings. If you’re unsure, check your model’s manual or find out how to locate your appliance’s model number before ordering.

Safety precautions before starting

• If working indoors, make sure there is adequate ventilation to prevent the buildup of exhaust fumes. Carbon monoxide poisoning can be a serious risk.
• Wear insulated work gloves to protect your hands from sharp metal parts, pinching hazards and debris.
• Never attempt to service or repair while it is running or when the engine is still warm. Wait for all moving parts to come to a complete stop.
• Exercise extreme caution when working near blades, augers, or any other moving parts. Keep your hands, fingers, and clothing clear of these areas at all times.
• If the appliance has recently been used, give it plenty of time for any hot parts to cool down before working on it. 
• Empty the gas tank before beginning any work. Refill using fresh fuel. 
• Clean up oil spills right away to prevent slipping or other damage. 
• 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.
• Take your time and don’t rush while working to prevent accidents and personal injuries.
• Work in a well-lit area so you can clearly see and access the interior parts.
• Clear your workspace of clutter and other obstacles. Keep children and pets away from the work area.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause injury.
• Wear safety glasses when working with chemicals, dust or cleaning large debris to prevent injury. 
• When not in use, store the machine in a safe and dry location.

Testing and replacing the capacitor

Step 1: Unplug and prepare the unit

1. Make sure the dehumidifier’s switched off, and unplug it from the outlet.
2. Move it to a stable, flat surface where you’ve got room to work and take things apart.
3. Remove the outer casing or panel. Some models have a bunch of screws or clips, keep them safe so you don’t lose any when putting it back together.
4. Find the capacitor; it’s usually close to the compressor or fan motor and looks like a small cylinder or oval with a couple of terminals and a metal or plastic shell.

Step 2: Discharge the capacitor

1. Grab a screwdriver with an insulated handle or a capacitor discharge tool. Touch the metal part across the capacitor’s two terminals to release any stored juice. Make sure the handle’s insulated so you don’t get zapped.
2. Once you’ve discharged it, switch your multimeter to DC voltage mode and double-check there’s no voltage left across the terminals.

Discharging makes sure there’s no leftover charge in the capacitor. Don’t rush this step, and definitely don’t skip it.

Step 3: Remove the wires from the capacitor

1. Take note of where each wire connects on the capacitor. Snapping a quick pic with your phone or labeling them with tape helps when putting everything back.
2. Use insulated pliers to carefully pull the connectors off the terminals.
3. Keep the wires tidy and within reach for when you need to hook them back up.

Step 4: Test the capacitor with a multimeter

1. If your multimeter has a capacitance setting, switch it to that.
2. Hook up the multimeter leads: red to one terminal, black to the other.
3. Check out the reading. A good capacitor should show a value close to what’s printed on it (so a 40 microfarad cap would read near 40). If it’s way off or reads zero, the capacitor’s probably toast.
4. If your multimeter doesn’t have a capacitance setting, it’s tougher to test. You might just swap in a new capacitor to see if that fixes things, or get a multimeter that can measure capacitance for an exact check.

Step 5: Replace the capacitor

1. Get a new capacitor that matches the voltage and capacitance of the old one. If you’re not sure about the specs, check your manual or find your model number to order the right part.
2. Put the new capacitor in place just like the old one, and make sure it’s secured with the bracket or clamp.
3. Reconnect the wires to the correct terminals. Refer back to your photo or labels to get them right.
4. Give each connector a gentle tug to make sure they’re snug.

Step 6: Reassemble and test the dehumidifier

1. Put the panels or cover back on the dehumidifier. Tighten up all the screws and make sure it’s all lined up.
2. Plug it back into the outlet.
3. Turn on the dehumidifier and listen for it to start up normally. The compressor or fan should kick in smoothly without loud humming or buzzing.
4. Let it run for a few minutes to make sure the fix worked.

Final thoughts

If you need dehumidifier parts or need some maintenance tips, head over to AppliancePartsPros.com. We’re on social media too, give us a follow on Facebook and Twitter for the latest news. Hit us up anytime if you need help finding the right part or troubleshooting any stubborn problems. We’re here to make sure you’ve got all the resources to keep your appliances running smoothly.

For personal assistance with your dehumidifier capacitor or other parts, give us a call at 1-877-477-7278 or visit AppliancePartsPros.com.