Your home’s plumbing is a complex, hidden network that you rely on every single day. It’s a classic case of “out of sight, out of mind”—we turn on the tap, we flush the toilet, and we simply expect it to work. But because this vital system is mostly behind walls and under floors, a sudden problem can be incredibly jarring and stressful.

When water starts backing up or a pipe starts leaking, it’s easy to feel a jolt of panic. While some issues are minor, many of the most common problems are signs of a deeper issue that requires a professional diagnosis. In those moments, having the number of a trusted local plumber on hand is the key to getting a fast and effective solution.

To help you understand what might be going on behind your walls, here’s a look at five of the most common plumbing problems we see in homes.

1. A Slow or Completely Clogged Drain

This is, without a doubt, the number one service call in the plumbing world. A drain that is slow to empty or is completely backed up is a frustrating and often messy problem. The cause usually depends on the location:

In the bathroom, the most common culprits in a bathroom sink or shower are a stubborn combination of hair, soap scum, and toothpaste that builds up over time. Kitchen sink clogs are typically caused by a buildup of fats, oils, and grease that gets washed down the drain and solidifies in the pipes, along with food scraps.

While a single slow drain usually points to a local clog, if you notice that multiple drains in your house (like a toilet and a nearby tub) are all draining slowly, this is a red flag for a much more serious problem in your main sewer line.

2. A Constantly Running Toilet

That incessant hissing sound of a toilet that never quite stops running is more than just an annoyance; it’s the sound of money literally going down the drain. A running toilet can waste hundreds of gallons of water a month, leading to a surprisingly high water bill.

Fortunately, the cause is usually one of two simple, inexpensive components inside the toilet tank: a faulty flapper (the rubber seal at the bottom of the tank) that isn’t sealing properly, or a misadjusted float that isn’t telling the fill valve to shut off.

3. A Dripping Faucet

A dripping faucet is the classic plumbing problem. While it might seem like a minor issue, that constant drip… drip… drip… can waste a shocking amount of water over time and leave ugly stains in your sink. The cause is almost always a small, worn-out part inside the faucet handle. In most cases, it’s a degraded rubber washer or a failing O-ring that is no longer creating a tight seal.

4. Low Water Pressure

Do you turn on your shower only to be met with a weak, unsatisfying trickle? A sudden drop in water pressure can be a frustrating and complex problem. If the low pressure is only happening at a single faucet, the cause is often a simple mineral buildup in the faucet’s aerator, which is an easy fix.

However, if you are experiencing low water pressure throughout your entire house, it points to a more significant issue. It could be a problem with the pressure-reducing valve on your main water line, or, more seriously, it could be a sign of a hidden water line leak somewhere on your property.

5. A Leaking Water Heater

A puddle of water around the base of your water heater is a major warning sign that should be addressed immediately. It can be caused by a few different things, but the most common cause for an older tank is internal corrosion that has finally created a small leak.

This is not a problem that will get better on its own. A small leak is often a signal that the tank’s structural integrity is compromised and that it is at risk of a catastrophic failure—a full-blown rupture that can flood your garage, basement, or utility closet. Maintaining your water heater is a key part of home safety and efficiency. At the first sign of a leak, it’s crucial to have it professionally inspected.

Understanding these common plumbing problems can help you spot them early. For anything beyond a simple clog, calling in a professional is the safest, fastest, and most effective way to protect your home.