If you suspect that your kitchen sink's drain may be clogging up, you may wonder if there is any other way to tell if there is a blockage before it completely stops up. If so, look for one or more of the following subtle signs that your kitchen drain is clogging up:

Sounds Of Gurgling From The Drainage Pipe

After you drain your dishwater, you may start hearing a gurgling sound coming from the drainage pipe under the sink. This is a sign that there could be a partial blockage near the elbow of the pipe. 

As the water tries to drain through the pipe, it can become trapped inside the elbow, which has a small amount of air in the top curve to keep gases from coming up out of the drain. As the water is slowed, these gases are mixed with the water. As they go through the blockage, the gas bubbles pop, making the gurgling noise.

Air Bubbles Pop Up While Your Dishwater Is Draining

If the blockage within your sink's drainage pipe has become large, you may start seeing air bubbles pop up into the water while the sink is draining. If the clog is inside the elbow, as discussed above, this could be the air trapped within it making its way up into the sink.

Another explanation is that the clog is causing uneven drainage into the pipe. Air pockets may start to form, and while you are draining your sink, they come up out of the pipe and through the drain. After you see several air bubbles, you may notice a slight increase in the rate at which the water drains.

Water Backs Up To The Drain Hole Before Exiting

Immediately after your sink is completely drained, look carefully at the drain hole as the last of the water moves through it. If there is a blockage in the pipe, you may see the water flow through, only to resurface to just below the hole.

Water backing up to the drain hole before completely exiting the pipe is a sign that it has been temporarily stopped by a clog. While the blockage is still small, it should eventually recede. However, if the clog is allowed to grow, you may not see the water recede. Instead, it may come back up into the sink where the water may stay until the blockage is cleared.

If you notice any of the above warning signs, your kitchen drain is most likely clogging up and should be inspected by a plumber before it becomes completely blocked. You may also want to contact a plumbing service to have them look at your drains to make sure they are all clear, including your main sewer lines. Click here to read more about unclogging your drains!