Why does a laundry drain need to be installed at a minimum height of 30″

drainwashing-machine

My laundry machine doesn't work properly in my new flat (the wash cycle never ends), and the instructions specify that the common cause of my problem is that the drain is too low (my drain is indeed at 15" above the machine bottom, whereas the instructions recommend 30").

I'm quite curious as to why this is the case; common sense dictates that too low a drain shouldn't be an issue, doesn't it?

Does somebody have an explanation for this requirement?

Best Answer

The water in the wash tub will drain out if the drain in the wall is lower than the water level in the washing machine. Simple physics, water seeks its own level. The drain located at the recommended height will allow the water to remain and allow the pump to remove the water at the end of the cycle.