Fixing a leak under the kitchen sink yourself is possible with the right knowledge and tools. Whether you want to prepare yourself in advance of any issues or have a leak that needs solving immediately, here’s what you need to know. In this blog post, we’ll discuss how to troubleshoot and fix common plumbing issues that occur under the kitchen sink.
Steps to Identifying and Repairing a Kitchen Sink Leak
The first time you notice a leak under your kitchen sink, start by assessing the situation. Grab a towel and bucket if needed to begin any cleanup associated with the leak, then focus on the culprit itself. Let’s address how to find the under sink leak, and your DIY repair options.
Step 1. Pinpoint the Source of the Leak
After cleaning up any water that has accumulated in the cabinet underneath the kitchen sink, start looking for the origin point of the leak.
There are several common sources of such leaks: the kitchen sink faucet, the kitchen sink drain, the water supply or the dishwasher. At times it could be a broken pipe or a pipe connection, the joints where pipes fit together. It’s often fairly easy to determine where the leak is coming from once you poke around with a flashlight.
Most commonly, water is leaking from the sink’s drain assembly or water supply. After you’ve dried the sink cabinet, try turning on the sink faucet and looking underneath. As the water runs down the drain, you should be able to see if the water is slowly dripping from one of the drain components. Or, when the water is running, you may notice the leak is coming from the water supply line.
At other times, the faucet itself could be the culprit. In this case, you’ll see water leaking at the base of the faucet, which could also be running down the back of the cabinet. This means you’d possibly see water pooling at the back of the cabinet and/or damage to the back panel.
Your plumbing system can last for many years, but it’s not infallible. The same applies for your dishwasher. If you’re having trouble identifying the source of the leak after testing and inspecting the kitchen sink drain and faucet, it’s possible that the issue could be associated with your dishwasher. Its drain hose and air gap are connected to the kitchen sink drain pipe or garbage disposal. Try running your dishwasher, making sure to closely inspect the appliance’s drain system.
Once you’ve pinpointed the leak, it’s time to move on to the next steps.
Step 2. Turn Off the Water and Gather What You Need to Make Repairs
Before you consider making any repairs to any of your plumbing components, turn off the water at the source. This is an essential step you cannot overlook. The turn off location may be under the sink, or elsewhere such as at the main water inlet line. As you make repairs, you may need to disassemble and loosen or tighten components on the water supply line, which could cause water in these supply pipes to shoot out. In addition, you may also need to turn on the kitchen faucet to let any residual water in the pipes to drain out before beginning repairs.
For your dishwasher, you should also unplug the appliance or turn off the breaker.
In most instances of leak repairs, you’ll need the standard tools found in a regular toolbox: flat head screwdriver, adjustable wrench, allen wrench and pliers. Note that if you need a replacement part, you’ll need to order the component based on the exact model of the original.
Step 3. Complete the Leak Repairs
Fixing a Leaking Kitchen Sink Drain
There are many components that make up the drain assembly, also called the P-trap. At times, the drain itself can become clogged, which can contribute to or exacerbate leaking issues. Pipes are not meant to hold standing water, so a blockage can cause water to slowly leak through joints and seals. In other scenarios, the connections or joints can become loose over time. If the nuts seem to be in good shape, you can often simply tighten them with pliers.
If you have a clogged drain, do not use a chemical cleaner because this can eat away at your garbage disposal as well as the blockage. Flush out the drain with hot water, and if that doesn’t work, mix together vinegar and baking soda.
Fixing a Leaking Kitchen Sink Water Supply Line
The water supply line has at least one connection where it attaches to the sink, which is often where leaks occur. You can use pliers or an adjustable wrench to tighten the nuts. If the water supply line is still leaking after you’ve adjusted the nuts, you may need a replacement water supply line.
Fixing A Leaky Kitchen Sink Faucet
When you’ve noted that the leak source is at the base of the faucet, you’ll need to disassemble the faucet. This is because it’s likely you’ll need to replace the O-ring, which forms a seal against leaking water but deteriorates over time. It’s a rubber disc that helps keep the faucet handle in place. Every type of faucet features an O-ring, but you’ll need to order a replacement one compatible with the manufacturer and model of your kitchen sink faucet.
Fixing a Leaky Dishwasher
Note that the general advice we give here does not supersede troubleshooting and repair instructions from the dishwasher manufacturer, but it can help give you an idea of what to look for when considering DIY repairs. It’s also worth repeating that the water and dishwasher itself should be turned off at this time.
One of the common issues caused by dishwasher leaks that occur underneath the kitchen sink is when the drain pipe or air gap gets clogged. The drain pipe from the dishwasher connects to your sink drain, with a section called the air gap in between in order to prevent contaminated water from flowing back into the dishwasher after exiting it. As we covered earlier in the blog post, drain pipes can easily leak when clogs occur because they’re not meant to hold water for extended periods of time.
To address clogs in the air gap, you’ll need to detach the top of this device, which is often located on the kitchen counter next to your sink basin, and get rid of any debris or food waste in sight. If the dishwasher air gap is clear, the clog may be in the drain pipe itself. In that case it’s best to pour a mixture of baking soda and vinegar into the bowl-shaped drain section at the bottom of the dishwasher. Give it a few minutes for the chemical reaction to occur then pour hot water down to flush out the dishwasher drain. If this doesn’t work, you may need to call a professional plumber.
In other scenarios, the dishwasher drain pipe itself may be leaking because the part is old and needs to be replaced.
Professional Assistance Solving Kitchen Sink and Dishwasher Leaks
Your home’s plumbing is subject to regular use, and resulting wear and tear, so it’s good to be prepared and know what to do when these kinds of leaks occur. When you experience leaks from your kitchen sink or dishwasher plumbing components, you’re now equipped with a quick guide to identifying and steps you can take to solve your issue. If you need professional leak repair, call our team at Atlas Home Services.
