The continuous drain has stopped working

Work down this list in order

1. 1Is the drain cap still fitted? Units with a threaded gravity port ship with a plastic cap in place so they drain into the bucket out of the box. Screw a hose onto the port with the cap still in and nothing comes out. Look inside the port, behind the bucket recess.
2. 2Is there a sag or a loop in the hose? Water pools in the low spot, the pool blocks the line, condensate backs up. Run your hand along the whole route - any section that is not falling is the fault. Coiled excess hose behind the machine is the classic version of this.
3. 3Is the destination higher than the outlet? A gravity drain cannot climb. If the hose goes up over a step, a pipe or a threshold anywhere on its run, gravity is not going to work regardless of how good the rest of the route is.
4. 4Is the outlet end submerged? In a sump, a floor drain with standing water, or a bucket, a submerged end will not free-drain and can siphon back.
5. 5Is the machine level? A unit tilted away from its drain port pools water in the tray. Check with a spirit level or a phone; the feet are often adjustable.
6. 6Is the hose blocked? Disconnect it and run water through from a tap. Condensate is fairly clean, but a hose that has sat in a damp basement for a season can grow a biofilm plug, especially at a narrow section or a join.
7. 7Is it a pump model that has stopped pumping? If the machine has a pump and it is not running, or is running constantly, the problem is the pump rather than the hose. Pump lift and distance.

If there is water on the floor

Different sequence, and treat it as urgent because water and a mains appliance are on the floor together. Unplug it first.

• Where is the water coming from? Under the machine, or from a hose join? A join is a washer or a cracked fitting and is an easy fix.
• Is the tray overflowing? That means condensate is being produced faster than it is leaving - a blocked line, a failed pump, or a tray that is not draining because the machine is out of level.
• Is it condensation on the outside of the machine? In a very humid room a cold surface will sweat. Uncommon on a dehumidifier casing but not unheard of, and harmless.
• Is the bucket seated properly? A bucket not fully home can let water past the seal. Remove it and refit it.

Preventing the repeat

• Cut the hose to length rather than coiling the excess. A coil becomes a sag.
• Support the run every few feet along a wall, rather than letting it lie loose on the floor where it will find its own low point.
• Flush the line once a season with clean water. Two minutes, and it clears the biofilm before it becomes a plug.
• Check it a week after setting it up. Most drainage faults appear over days as the hose settles, not in the first hour.
• Switch to the bucket in freezing weather if the line runs outside. A frozen outlet backs the whole line up.