What's the first thing you should check if a newly installed faucet starts leaking? What installation errors are most common, and how can they be corrected?

Question

When a newly installed faucet starts leaking, it can be frustrating and perplexing. four industry leaders, a Plumbing Manager and a Lead Plumber, share their expert advice on troubleshooting this common household issue. Discover why the first step should be to check the aerator for debris and finish with tips on examining the shutoff valves, as well as other insights in between. This article presents 4 invaluable insights from seasoned professionals to help you solve the problem efficiently.

Jonathan Cannon · Answer

No one likes a new faucet install that starts leaking. I like to check the aerator first for debris. If there's some trapped in there, then it's likely debris got into the cartridges also. Another good rule is to always check your incoming pressure to the home. The PRV (pressure-reducing valve) may need a rebuild/replacement, or maybe they don't have one at all. If everything checks out, then it's time to pull the cartridge/cartridges and see if there's an abnormality. Clean out any debris, make sure everything looks good, reassemble, and test. Lastly, never rule out manufacturer defects or poor handling in shipping. In my experience, always spend a little more money on the faucet, and you'll avoid all this.

Michael Baker · Answer

First thing to check is, where is it leaking? The supply lines? The spray head? Or, heaven forbid, is it coming from the body of the faucet itself? It's not uncommon to forget to cinch down a supply line and get a small dribble. Easy enough to fix, as is the sprayer head. A little tightening and you're good. However, if the lines inside the faucet get rubbed or pierced for any reason, you will have to replace the faucet.

Blake Beesley · Answer

Start by checking the connections under the sink, especially the supply-line fittings. A loose or improperly seated connection is often the culprit. If it's snug but still leaking, inspect the faucet's base; skipping the gasket or failing to use plumber's putty during installation can cause water to seep.
The most common errors we see are over-tightened connections, which can damage threads, and improperly installed washers. To fix these, loosen and realign the parts, ensuring washers and gaskets are correctly positioned. Hand-tighten connections first, then give them a small turn with a wrench—just enough to secure without overdoing it.

Dane Edmonds · Answer

Having no other information than what is described, my first check is the shutoff valves. It is very common for the packing nut behind the handle to be loose after the valve has been turned off and turned back on. Shutoff valves (angle stops) will sit untouched for years, and plumbing likes to remain static, so shutting a valve and opening it back up will almost always have some failure or need a remedy.

How to Identify and Correct Common Installation Errors for Leaky Faucets

How to Identify and Correct Common Installation Errors for Leaky Faucets

Check the Aerator for Debris

Identify the Source of the Leak

Inspect Supply-Line Fittings

Examine the Shutoff Valves