RV Kitchen Sink Leaking Underneath – 6 Causes To Fix

After completing the lunch with your mates, you got into cleaning the dishes. Suddenly, you notice the water is dripping underneath the RV sink. You started scratching your head by thinking why it is happening?

The reasons behind your RV kitchen sink leaking underneath include a loose/defective faucet, damaged O-ring, and jammed p-trap. Besides, corroded valves and old putty can cause significant leakages.  

There are some other reasons causing this huge bummer. This guide will walk you through all the details of leakage locations, causes, and quick troubleshooting!

RV Kitchen Sink Leaking Underneath

Where Can You Detect RV Kitchen Sink Leakage?

Even though it sounds like you can easily locate the RV kitchen sink leakage that would be anywhere underneath, the reality is different! You can detect it on the pressurized pipe, drainpipe, or somewhere else. 

For instance, people can notice water spraying in all places if the leakage appears on the pressurized pipe. In contrast, you can end up with a pool of water underneath the RV’s cabinet in case there is a leakage around the drainpipe. 

By taking assistance from a flashlight, you can inspect for leakages where the sink basin meets the pipes. You must observe every single pipe to find the potential RV sink leakage underneath. 

If possible, look at the supply lines and shut-off valves of your RV’s sink. Thus, you can ensure whether there is any visible mineral build or rust causing sink leakage. 

Why Does an RV Kitchen Sink Leaking Underneath?

As you saw, there are numerous places where the leakage can appear underneath your RV kitchen sink. In the same way, the reasons why leaks occur are many, and these include –

  1. Faulty O-ring
  2. Loose Faucet or Defects
  3. Rusted Valve
  4. Old Putty
  5. Jammed P-Trap
  6. Excessive Water Pressure

From the above reasons, you may get an idea that the leakage can be visible on a single or multiple components. 

So, there is no shortcut or a single best way to get rid of leaking issues with your RV! Rather, you must deal with them individually, depending on where the sink is leaking underneath. 

How to Fix RV Kitchen Sink Leaking Underneath? 

When it comes to troubleshooting, some steps will seem to be easy-peasy, while others can be back-breaking! 

In fact, some situations may require you to call an expert plumber to deal with the tough situations. So, sit tight, and let’s get into the troubleshooting processes of each –

01. Change the O-ring

The O-ring is considered a crucial component of the faucet. It is liable to hold the handle of the sink’s faucet in place with the assistance of some screws. 

Talking about the functionality, it keeps the water from getting leaked from the spout base. 

So, it is pretty common to end up with sink leakage underneath if it is loose or worn out. In that case, you must tighten it or replace it with a new one.

Read Also: AO Smith 2-stage Water Filter Leaking | Here’s What You Can Do!

02. Tighten the Faucet or Check the Defects

A loose faucet will surely be one of the prime reasons behind sink leakage underneath. And it happens if you or your plumber fail to install it in the way it should be! 

In addition to that, the sink faucet may also develop interior leakage, which basically occurs because of aging, cracking, and parts’ failure. 

As a result, water starts dripping out and eventually causes serious sink leaking. 

Calling an expert will be the best way to eliminate faucet-related issues, especially if there is something that you cannot fix. 

In contrast, some basic uses of wrenches can be enough if the leakage is occurring only for being loose. Some experts suggests using a basic wrench to deal with such plumbing tasks. 

03. Change or Replace the Valve

Almost every RV kitchen sink requires a few valves in terms of controlling the flow of the water. 

And thus, it keeps the pipe out of getting leaked. But over time, it is also prone to damage or corrode, resulting in compromising the seal. 

The valve that creates a connection between the spout and faucet is known to be a “valve seat.” 

This critical valve can also get corroded over a period of time, which will ultimately result in the sink leaking underneath. 

Speaking of the solution, all you need is to change it right away. While replacing it, you must turn off the water connection to prevent excess water dripping.

Read Also: 7 Reasons Why RV Water Pressure Starts Strong and Then Drops

04. Add New Putty

In order to prevent leakage, plumbers often use putty around the kitchen sink’s drain. So when it completely dries out or becomes thinner day by day, the sink’s drain will develop leakages underneath. 

But guess what? Fixing this issue is completely hassle-free, as you will only need to incorporate a new putty in place of the old one. You can also take assistance from Teflon pipe ribbon as an alternative. 

05. Eliminate Clogs from P-Trap

In a nutshell, a p-trap refers to a curve-shaped pipe located underneath the kitchen sink. It is mainly responsible for passing wastewater from your kitchen sink. 

So, this may get clogged or sometimes leaked after long-term use. In particular, it is prone to block the water flow when residue or gunk builds up over the period. 

Thus, it results in overflowing and significant leakage, which you should fix by getting a helping hand. 

Ensure to call an expert to unjam the p-trap or replace it with a new one if it becomes useless. 

06. Install Water Pressure Regulator/Consult an Expert

If the leakage problem underneath the sink is occurring due to excessive water pressure, it is not something you can easily fix, to be honest! 

Like, sometimes, incorporating a water pressure regulator might work to reduce extreme water pressure so that there will not be any leakages. 

But if it fails to work, take assistance from a Teflon tape to add it towards the leaky spots. However, if none of them cannot solve the issue, consulting a plumber will be the only solution!

Read Also: 5 Most Common Reasons Why RV Shower Leaking Behind Wall


You can prevent kitchen sink leakage underneath by following some tips. So let us help you how to do so with answers, including some more helpful queries to let you get more education regarding sink leaking: 

Is there any way to prevent RV kitchen sink leakage underneath?

Regular monitoring and maintenance are the best ways for RV kitchen sink leakage prevention. Pay attention to the components that are prone to corrode so that you can replace them while needed. Observing the water pressure is equally necessary. 

What is the reason behind the RV kitchen drain pipe leakage?

Improper sealing has been the core reason why the RV kitchen drain pipe leaks underneath. Besides, there can be a defective O-ring that causes the water to leak once you turn the faucet on. 

Which putty is effective in fixing RV sink leaks on faulty pipes?

Experts recommend using epoxy putty to fix leaky pipes in the best way possible. Basically, epoxy putty turns into a solid hardened surface once you apply it to the leaky spots. And thus, it seals tiny leakages effectively! 

Final Words

It is a waste of money to call a plumber directly if you start noticing RV kitchen sink leakage underneath. 

Because some issues can be fixed by applying quick DIY hacks, which is what we already discussed. 

However, you should not take any risk if there are major leakages. Otherwise, excess water flow can create a huge mess inside your RV!

Read Also: Why RV Water Pump Not Working When Winterizing? (Solved)

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