DIY Network

How to Install a Dehumidifier Pump

Ed the Plumber host Ed Del Grande explains how to install a pumping system that will clear out a dehumidifier's bucket so it will work more efficiently.

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Step 1: Connect the Condensation Pump

Locate the sump. This is where the condensate pump will empty. A sump is like a pit, or floor drain with gravel in the bottom (Image 1). The location of the dehumidifier should be air tight; open air supplies push moist air in. Dehumidifiers also should not be placed in heavy traffic areas, and there should be at least 1' of clearance around the unit. Once you have located the dehumidifier, connect the condensation pump. Remove the dehumidifier's collection pail, and then choose a paddle bit that's slightly smaller than the size of the hose adaptor knockout. Carefully use a drill to open up the hole (Image 2).

Step 2: Attach the Hose

Take a washing machine hose or short piece of a garden hose and attach the threaded female end onto the dehumidifier's tank. Cut the other end off of the hose, and then insert it into the drain inlet on the condensate pump housing. Be sure that the end of the hose is at least 1-1/2" above the bottom of the reservoir. Secure the hose to the housing with a zip tie. Be careful not to pull the tie too tight.

attach hose to dehumidifier and drain inlet

Step 3: Install Ground Lift Adaptors

At least two outlets are needed. Be sure to check the manufacturer's instructions to ensure that the circuit breaker has enough power to run the dehumidifier. Most dehumidifiers require a 20-amp breaker. Install ground lift adaptors if you only have two-prong outlets. Secure them to the cover plate screw. Before running the condensate drain to the sump, ensure that the hose from the dehumidifier is secured to the condensate pump.

install ground lift adaptors for two prong outlets

Step 4: Install an Alarm

Install an alarm that will sound to warn when there's a problem with the unit such as a leak. Remove the motor cover, and then remove the yellow lead from the bottom terminal and move it to the middle terminal, making sure not to touch the other wires. Replace the cover. Using a low-voltage alarm, put the yellow leads on the pump onto the place of the door bell described in the manufacturer's instructions. Connect the leads from the pump into the alarms leads. To test the alarm, make sure the pump is not plugged in but that the alarm is. Pour water into the condensation pump until the alarm goes off, which should be when the water reaches the top.

install an alarm for pumping system

Step 5: Move the Water to the Sump

To move the water from the pump to the sump, use a clear plastic 3/8" flexible hose if the length is less than 10'. Use 3/4" PVC pipe if it's more than 10'. Use a transition fitting to connect the plastic tubing to the PVC. Glue the fitting on one side, and then a barbed fitting on the other that will connect to the plastic tubing. Wrap the threads of the barbed-to-machine threaded adapter with Teflon tape. Hand screw it into a PVC 3/4" to 1/2" threaded bushing. Use a pair of slip-joint pliers to snug it down. Be sure to not over tighten.

moving water to sump

Step 6: Push the Pieces Together

Use PVC cleaner to clean the other end of the bushing and both ends of a 3/4" PVC coupler. When the cleaner is dry, apply PVC glue to the bushing and one end of the coupler. Be careful to keep the glue off of the barbed side of the bushing. Pushing the pieces together, slightly twist them as they slide into place. Be sure to hold the two pieces together to prevent them from pushing apart. Let the fitting completely dry before connecting the plastic hose.

Step 7: Run the Drain Lines

Run the PVC drain lines. Make sure the lines are pitching downward, so that gravity pulls the water down and out. Drill through the wall behind the dehumidifier, and then work the hose into the hole.

run the PVC drain lines

Step 8: Measure and Cut the PVC

Measure and cut the PVC sections so that the end of the pipe will be directly in the sump. This will help to avoid any spillage or splash. Use 90-degree elbows and couplers to work the PVC pipe back to the condensate pump -- cleaning and gluing the connections as you go. Be sure that the line runs down hill toward the sump, and then secure the pipe with clamps. When making turns on the horizontal sections of the pipe, use 45-degree elbows to make the turns gentler, this will help avoid any water hammer noise.

measure and cut PVC sections

Step 9: Connect the Hose

Connect the hose to the PVC adaptor at the end of the PVC. Work the hose from the wall to the fitting, and then cut it to length. Attach the hose to the barbed fitting and secure it with a zip tie.

connect hose to PVC adaptor

Step 10: Test the System

To test the system, make sure that the dehumidifier and the condensate pump are plugged into an outlet. Pour a bucket of water into the system, and then check all of the plumbing joints for leaks. Also, check the sump area.