Why are drains so important to keep clean?

Drains get backed up anywhere and this causes multiple problems. For example, a drain stand pipe for your washer gets clogged the water can spray anywhere like putting your thumb on a garden hose. This makes you think you have a leak in the washer but it's the drain causing it. Next a partially clogged drain can back up to where it's siphoning out your water as it's filling. This usually creates the long fill error and can happen if your drain hose is more than 6 inches down stand pipe.

A dishwasher that doesn't have a syphon break will eventually back up and this will give you what we call grey water in your dishwasher. It's smelly discolored water that appears at the end of a cycle or if it gets too bad you won't even be able to start it. Even if you have a syphon break and something gets stuck at top of the air gap it won't drain.

Floods are always caused by inability to drain the excess of the liquids. So keep the lines clear and get them cleaned every 6 months and you will need less repairs. And to have maintenance service as opposed to waiting for a backed up drain makes the most cost effective sense for extended life of the appliance and less costly repairs on them.