Dishwasher Siphoning Out

httpvh://www.youtube.com/watch?v=hpfcIuLLIYQ

This is a cool problem that can sometimes be hard to catch. What is happening here, is when the dishwasher goes into drain, it starts a siphon. The siphon then pulls all the water out of the machine and if it is strong enough it will also pull out the next fill. This situation occurs primarily when the drain is installed straight down into the basement instead of into a drain stub under the sink in the kitchen. When it is installed under the sink, the level of the drain is higher than the water level in the dishwasher and a siphon cannot start. However, with the drain below the level of the water, siphoning can occur. I find that even with a high loop installed on the side of the dishwasher, if the drain goes straight down from the loop a siphon will still be created. The only way to really stop this is to install an ‘air-gap’ or a ‘siphon break’ into the drain line which will allow air into the loop and prevent any siphon from occurring.

With this unit, the water siphoned out and then the heater came on to heat the water (that was no longer in the unit.) This created a higher amp draw than normal because no water was flowing over the element, which in turn took out the safety fuse in the control panel area.

This customer will have his installer back into reroute his drain.