When hose is attached, bucket fills up

For the hose to work the unit must be elevated somehow so that the bucket will not fill. Or somehow the unit must be higher than the end of the hose. If you put the hose down an open floor drain that should suffice.

Attach a length of garden hose no longer than 5 feet, to the threaded drain hose connection that was supplied with your unit, to carry water to the drain.
1. Remove the drain-hole cover on the back left side of your unit.
2. Connect a garden hose to the threaded drain hose connector.
3. Push hose connector tightly to the drain-hole on Rear Grille with the arrow on the tab pointing UP.
The hose attachment will accept a standard garden hose fitting.
Do not over tighten the hose when connecting it to the hose connector,
use a rubber washer and tighten by hand firmly without stripping the
plastic threads.
When being attached to hose connector drain hose connection,
do not bend or kink the hose. The hose should lie flat from the
dehumidifier to the drain.

My humidifier has a knockout inside the hose connection, that you have to remove. simple but check it out.

Most of the units do not require the bucket to be in place, when the hose is attached. However, since you didn't list the Model Number of your unit, I can't be sure that's the case with yours. However, if you click on the following link, and enter the correct model number, you can download and print the Owners Manual for future reference.

http://whirlpool.com/custserv/index.jsp

Hope this helped you to sort it out.

Was the hose attached to the bucket or directly attached to the inside of the humidifier?
If it was to the bucket, the hose may have slightly pulled the bucket out of place, disengaging the safety switch. Unplug the unit and wait 5 minutes. Then plug the unit back in. Turn it to ON and remove the bucket and carefully reinstall it. You should hear a "click" sound when it's properly in place and the unit should start back up,

Hope this helps to solve your problem.

My DH 304 is a hand-me-down so I don't have a manual but it did come with a hose attachment which is plastic tube with a threaded end to which you attach a hose. The other end of the tube goes through a hole in the back of the unit and then through a foam screen inside the unit to slip over the drain plug. Aligning the tube and the drain plug can be tricky; it is helpful to remove the bucket to see if you're getting the tube onto the drain plug. Once you have the tube attached to the drain plug, align the tube in the hole in the rear of the unit so that the tab on the tube is inserted into the slot at the hole in the back of the unit.

Check to ensure the hose is connected to the outlet of the pump correctly.

Sounds like the connector hoae came off inside the machine . Look up inside the machine where the bucket would go and you should see where the hose attaches to the condensate drain . It might have pulled off .

A regular brass 3/4" FIP to 3/4" MHT connector with a garden hose washer between the bucket and brass connector was close enough to make things work.

I bought one of the FDL70S1 Frigidaire dehumidifiers today for my shop, and found that the $5 hose I bought to drain it through the floor wouldn't tighten down completely, allowing the hose to twist and wobble, a sure indication that it was not water tight. Simply adding a second washer, as described in another answer here, allowed me to tighten the hose sufficiently to produce a tight fit with no play between the hose and the dehumidifier. It hasn't leaked. I know it is a threads-per-inch issue, and I am stumped as to why Frigidaire would supply these units with a different thread pitch than the standard GHT (garden hose thread) 3/4" - 11.5 tpi. The threads on the unit appear to be 3/4 NPS - 14 tpi. Go figure!