The water from your dishwasher drain and your sink flow through the same drainage line. So, any clogs or blockages within that main drain line can cause water to back up and overflow. If this is a reoccurring problem, occasional maintenance and simple cleaning may be your answer.
Drain Clogs
As the dishwasher pumps out water, the clog can cause a backup, resulting in water filling the sink. Solution: Start by using a plunger to attempt to dislodge the clog. If that doesn't work, try a drain snake or a mixture of baking soda and vinegar to break down the blockage.
If the drain is not partially clogged and if the dishwasher is installed correctly, the discharge hose should rise above the drains of the sink, before coming down to the disposer inlet. This will prevent backflow into the dishwasher. Make sure the drain hose is above where it attatches to the drain.
When the drain is clogged, pressure in the pipe can cause water to back up into the dishwasher. To alleviate this problem, you can try and remove the P-trap underneath the sink and clean out the gunk. Don't forget to put a water bucket under the pipe first!
Water on the kitchen floor in front of the dishwasher could indicate a leaking door gasket. It's easy to find out – simply open the dishwasher and check the seal around the door. If you see ripped or worn-out sections, replace the gasket before you run the appliance again.
A mixture of equal parts baking soda and vinegar may unclog dishwasher drains. Pour the solution into the basket at the bottom and let it sit for 15 minutes. Then, pour hot water down the basket and run the rinse cycle.
Most dishwashers feature a long drain hose that connects the appliance to either an air gap or disposal hookup for drainage. And over time, these hoses can easily become kinked, twisted, detached, or blocked – all of which prevent proper discharge and lead to water backups.
CHECK YOUR DRAIN MOTOR, DRAIN VALVE AND DRAIN HOSE
A broken drain motor or a clogged drain hose can also cause standing water in your dishwasher. A stuck drain valve bracket may indicate burnt out electrical components in your dishwasher. All of these issues are better left to the professionals.
Where is the dishwasher air gap located? The dishwasher air gap is a chrome or stainless steel cylinder fitting that can be found at the back of the sink near the faucet.
Most dishwashers do not have built-in backflow prevention on the drain hose side. This is where the drain air gap device functions; to prevent contamination of the inside of the dishwasher. This type of contamination would occur if there was a kitchen sink drain backup.
This is usually caused by a blockage in the drain pump, such as a piece of broken glass or some other foreign object. If you break a glass or similar item in the dishwasher, it's important to make sure you thoroughly remove all the glass to prevent such blockages. This includes checking and clearing the filter.
If you do not have a backwater valve, plugs with backflow devices can be installed in floor drains. These plugs have a ball or float that will stop water or sewage from backing up into a home while permitting water to flow into the drain. These plugs can be left in place year-round.
Drain Hose Air Gap
Some dishwasher drain hoses use an air gap to create a section of air in the dishwasher drain line hose loop to prevent dirty sink water from flowing back into the dishwasher. It usually looks like a silver cylinder set close to the rim of the kitchen sink near the faucet closest to the dishwasher.
This type of plumbing backup can get messy and usually means there's a clog further down your drainpipe or there is an issue with the drain box. This type of issue often happens beyond the sink and makes it so water can't properly escape or drain.
The air gap resembles a short, squaw cylinder that may appear to have open valves on one or both of its sides. Your sink faucet sits several inches higher than your sink rim to protect against sink water overflowing to the point that it could re-enter the faucet line where your clean water comes from.
If you find that your dishwasher is leaking from the bottom, this is most likely due to a leaky gasket and can be indicated by water on the floor in front of the dishwasher. If you notice that the dishwasher is leaking from underneath, you could also have a cracked hose or faulty valves connection issue.
Signs pointing to a faulty inlet valve include: Leaks that fill the dishwasher when it's off. Inadequate water for a cycle. The dishwasher fills too slowly or not all.
Average Lifespan of Dishwashers
According to reputed appliance repair technicians and manufacturers, the average home dishwasher lasts between 10 to 15 years with regular use and proper maintenance. Even an appliance from the best dishwasher brands will only last 15 to 20 years at most.
In many homes, kitchen appliances and the washer drain through the same pipe. Grease and food often build up in that pipe, slowing the water flow. If it gets bad enough, it might stop altogether. This not only backs up kitchen appliances but can also back up your washing machine as well.
Clean the drain
Since it is common for debris to get stuck in the dishwasher drain, try cleaning it with a solution of equal parts baking soda and vinegar. Pour the baking soda and vinegar into the bottom of the dishwasher and let it sit for 15 minutes. Then run a rinse cycle at the highest heat setting.
Pour Boiling Water: This is an excellent way to unclog your dishwasher and help break up any built-up grease that causes a clogged dishwasher drain. Fill a pot with boiling water and pour it over the dishwasher drain. Let it sit for 10-15 minutes before running a cycle.