DIAGNOSIS Incorrect hose setup or an air lock in the line preventing proper siphon flow. The drain port is gravity-fed, so the hose must run downhill without any kinks or loops.
FIX Unplug, empty bucket. Ensure the rubber drain port plug is completely removed. Push your vinyl hose onto the port firmly—it needs a tight seal. Run the hose in a straight, downward line to your floor drain or pump. For every foot the unit is off the ground, you need at least a quarter-inch of downward slope in the hose.
IF THAT DIDN'T WORK Prime the hose. Detach it from the dehumidifier, pour a cup of water into the hose to fill the initial loop, then quickly reattach it to the port before the water drains out. This starts the siphon.
HEADS UP Never let the hose end sit in standing water in a drain pan—this creates a back-pressure seal that stops flow. The hose end must be open to air, hanging freely into the drain.