Empty the tank by hand or set up automatic drainage
A dehumidifier collects water in one of two ways: into a removable tank that you empty by hand, or through a drain hose that runs to a floor drain or sink. If your unit has a tank, you'll need to empty it when it fills up—usually every 12 to 24 hours in a damp room, though this varies by room size and humidity level. If your unit has a drain hose, you can set it up once and let water flow out continuously without touching anything.
Most portable dehumidifiers come with a tank. Larger units and whole-home systems usually have drain hose connections. Check your manual or the back of your unit to see which type you have.
Key Takeaways
- Empty a dehumidifier tank by pressing the release button or latch, sliding the tank out, and pouring the water down a sink or drain.
- The tank will feel heavy when full—typically 10 to 15 pounds of water depending on the model—so use both hands and pour slowly to avoid spilling.
- If your dehumidifier has a drain hose connection, attach a hose to the outlet and run it to a floor drain, sump pump, or sink to avoid emptying by hand.
- Most units have a float switch that stops the compressor when the tank is full, but continuing to run a full tank can damage the unit over time.
- Empty the tank at least once a day in humid conditions, or whenever the unit shuts off on its own.
How to remove and empty the tank
Locate the tank on your dehumidifier. On most portable units, it sits at the bottom front or bottom side of the machine. Look for a release button, latch, or handle—usually plastic and colored differently from the unit body. Press or pull this release while gently tugging the tank toward you. The tank should slide out smoothly; if it's stuck, check that you've fully released the latch.
Carry the tank to a sink or floor drain. A full tank weighs 10 to 15 pounds depending on your model, so use both hands. Tilt the tank slowly and pour the water down the drain. Pour from the corner of the tank opening, not straight down the middle, to control the flow and avoid splashing. If your sink is small, you may need to empty the tank in stages.
Slide the tank back into the unit until you hear or feel it click into place. Make sure it's seated fully—an improperly installed tank can leak water onto your floor or trigger a false "tank full" alert.
Setting up a drain hose to skip manual emptying
If your dehumidifier has a drain outlet (a small threaded or snap-fit connection on the back or bottom), you can attach a drain hose and let water flow out on its own. This is the best option if you don't want to empty a tank daily. Most dehumidifiers come with a drain hose adapter or hose kit; if yours didn't, you can buy a replacement hose at a hardware store—standard sizes are 5/8 inch or 3/4 inch diameter.
Attach the hose to the drain outlet by twisting it on (if threaded) or pushing it onto the fitting (if snap-fit). Run the hose to a floor drain, basement sump pump, laundry sink, or utility sink. The hose does not need to be elevated; gravity will pull the water down as long as the outlet is lower than the drain destination. find the hose with a clip or tape so it doesn't kink or come loose.
Once the hose is connected, you can leave the dehumidifier running without emptying the tank. Water will flow out continuously. Check the hose occasionally to make sure it hasn't come loose or clogged with mineral deposits.
What happens if you don't empty the tank
Most dehumidifiers have a float switch inside the tank. When water reaches a certain level, the float rises and triggers a switch that shuts off the compressor. This prevents the tank from overflowing onto your floor. However, the unit will stop removing humidity from the air once the tank is full, so your room will stay damp.
Leaving a full tank in the unit for extended periods can damage the compressor or cause water to leak around the tank seal. Some units will display a "tank full" light or beep to remind you to empty it. If you ignore this signal, the dehumidifier will straightforward stop working until you remove and empty the tank.
How often to empty the tank
Tank emptying frequency depends on room size, humidity level, and dehumidifier capacity. In a very damp basement or bathroom, a small portable unit may fill in 12 to 18 hours. In a moderately humid bedroom, it might take 24 to 48 hours. Larger units or those in drier rooms may need emptying only every few days.
The best approach is to check the tank once a day. If it's full or nearly full, empty it. If it's still mostly empty after 24 hours, you can check less often. During very humid weather or if you've just had water damage, check more frequently. Once you've run the unit for a few days, you'll develop a sense of how often your particular room requires emptying.
Cleaning the tank while you empty it
The tank collects only water, not dirt or debris, so it rarely needs scrubbing. However, mineral deposits from hard water can build up on the inside over time, especially if you live in an area with high mineral content in the water. If you notice white or tan buildup, rinse the tank with clean water and wipe it dry before reinstalling it.
If mold or algae appears inside the tank (rare, but possible in very humid climates), rinse it with a 1:1 mixture of white vinegar and water, scrub gently with a soft brush, and rinse again with clean water. Dry the tank completely before putting it back in the unit. Do not use bleach or harsh chemicals, as residue can damage the float switch or seals.
Troubleshooting tank and drainage problems
If water leaks around the tank when it's installed, the tank may not be seated properly. Remove it, check that the rubber seal around the opening is clean and not cracked, and slide the tank back in firmly until it clicks. If the seal is visibly damaged, you may need to order a replacement tank from the manufacturer.
If you've set up a drain hose and water is not flowing out, check that the hose is not kinked or pinched. Blow gently into the hose to see if it's clogged with mineral deposits. If it is, disconnect the hose and flush it with warm water. If the hose is clear but water still won't flow, the drain outlet on the unit may be clogged; consult your manual for instructions on clearing it, or contact the manufacturer.
If the unit shuts off frequently even though the tank doesn't feel full, the float switch may be stuck. Remove the tank, look inside for any debris or mineral buildup around the float mechanism, and gently clean it with a soft cloth. Reinstall the tank and try again. If the problem persists, the float switch may need replacement—this is a job for a technician.
Frequently Asked Questions
Can I pour the dehumidifier water down the toilet?
Yes. Dehumidifier water is distilled and contains no chemicals or contaminants, so it's safe for any drain. Some people collect it for watering plants or cleaning, though this is optional.
What size hose do I need for the drain outlet?
Check your dehumidifier manual or look at the drain outlet fitting. Standard sizes are 5/8 inch or 3/4 inch inside diameter. Measure the outlet or bring a photo to a hardware store and staff can help you match the right hose.
Does the dehumidifier have to sit level for the drain hose to work?
The unit itself should sit on a level floor for normal operation, but the drain hose does not require the unit to be perfectly level. Water will flow downhill through the hose as long as the outlet is lower than the drain destination. A slight slope helps, but is not necessary.
How do I know if the tank is full?
Most units have a "tank full" light or indicator on the control panel. Some also beep. If your unit doesn't have a light, lift the tank slightly—a full tank will feel noticeably heavier than an empty one. You can also remove it and look inside.
Can I leave the dehumidifier running with a full tank?
The float switch will shut off the compressor to prevent overflow, so water won't spill. However, the unit will stop removing humidity, and leaving a full tank in place for days can damage seals or the compressor. Empty the tank as soon as the unit signals it's full.