A single pinhole leak in a copper pipe is often a repair job. A second one, or a third in a different part of the house, raises a different question: is this one bad spot, or is the pipe wearing out? Your leak history is the best clue you have, so start keeping one.
What is a pinhole leak?
A pinhole leak is a very small hole in the wall of a pipe. It may spray a fine mist, drip inside a wall, or show up as a stain, a damp spot or a water bill that doesn't add up. Because the hole is small, it can go unnoticed for a while.
Don't ignore a leak just because it's small. Water inside a wall can damage what's around it before you notice anything.
What causes pinhole leaks in copper?
Nobody can name the cause from the outside. Copper can wear from the inside, and the water, the way it moves through the line, and the pipe itself can all play a part. Sorting out which one applies to your home takes a closer look, sometimes including a test of your water.
Hardness is the number people tend to reach for first. Look up your own water provider's report, because providers differ, and some don't publish a hardness number at all. As one example, EPCOR's 2025 Water Quality Report for Sun City West says: "The hardness in your water ranges from 3 to 11 grains per gallon (gpg)." A hardness number describes minerals in the water. On its own, it doesn't tell you why a particular pipe failed.
Live in Sun City West? Our Sun City West page covers the area.
Is one pinhole leak a patch job?
Often, yes. If it's your first leak and the rest of the plumbing has been quiet, a repair at that spot may be all you need. A repair fixes the spot that failed. It says nothing about the pipe right next to it.
So ask the plumber to look at the pipe around the leak, not just the hole. Pipe that looks worn near the repair is useful information. So is pipe that looks fine.
A repair done well should hold at the spot it covers. The open question is the next weak spot, and no repair at the first one can promise anything about that.
How many leaks make a pattern?
Nobody can give you a leak count that means "repipe," and anyone who tries without seeing your house is guessing. What matters is the shape of the history. Look at three things:
- When. Leaks that come close together in time look different from leaks years apart.
- Where. Leaks in different rooms can point to a wider problem than leaks in the same run of pipe.
- Which line. Hot, cold or both. Write it down, because the plumber will ask.
One leak, then quiet for a long stretch, looks like an isolated failure. Leaks that follow one after another, in different rooms, look more like a pattern. It's a judgment call, and a licensed plumber who has seen your pipes is in a better position to make it than a blog post is.
What should go in my leak log?
Start one now, even if you've only had one leak. A notes app works fine. Write down:
- The date, and the room.
- Whether it was a hot line, a cold line, or you couldn't tell.
- How you found it: a stain, a sound, a damp spot, a bill.
- What the plumber did and what they said about the pipe nearby.
- Photos of the leak and the damage.
That one page will save you time on every future call, and it gives a plumber something real to work from if a second or third leak shows up.
Should I test my water before I repipe?
If pinholes keep showing up, ask the plumber whether testing your water makes sense before you replace any pipe. Replacing pipe without knowing why it failed can leave you wondering whether the same thing will happen again. A test may not give a clear answer. It's still a fair question, and how the plumber responds tells you how carefully they're thinking about your house.
When does repiping come into the conversation?
Repiping means replacing the water lines that serve the house instead of fixing them one leak at a time. It's a bigger decision, and it's worth considering once you stop believing the last leak was a fluke. Our guide to when to repipe a Valley home walks through that decision. If you're weighing materials, the copper vs PEX comparison puts the two side by side.
What does patching cost over time?
Each patch feels small. The costs add up in ways that are easy to miss: repeat service calls, damage to drywall, flooring and paint, and the stress of wondering where the next one will show.
A repipe is a larger single decision. We won't guess at numbers, because the price depends on your house. The factors are how many lines are involved, how easy the pipe is to reach, what has to be repaired afterward, the material you choose, and permits and inspections, which vary by city. Ask for a repipe quote and a repair plan side by side. Either way, we give you the price before we start, and you approve it first.
When should I call a licensed plumber?
Call for any active leak. If water is near outlets, appliances or the electrical panel, stay clear of it, shut off the water at the main if you can do so safely, and call a licensed professional right away.
For a repeat leak, bring your log. Ask the plumber to look beyond the hole, to explain what they see in the pipe, and to walk you through both paths: repair and repipe. Permit rules vary by city, so ask about those too.
One leak is a repair. A string of them is a bigger decision, and your log is how you tell the two apart. If your copper keeps springing leaks, talk with us about repiping.
Common Questions
Copper can wear from the inside, and the water, the way it moves through the line, and the pipe itself can all play a part. A plumber has to look at your pipes, and sometimes test your water, to say which applies to your home.
A repair done well should hold at the spot it covers. It cannot promise anything about the next weak spot, so ask the plumber to look at the pipe around the leak too.
Look at when the leaks happened, where in the house they were, and which line they were on. Leaks close together, in different rooms, look more like a pattern than a single failure. A licensed plumber can help you read yours.
That depends on your house and your plumber's advice. Our copper vs PEX comparison lays out how the two compare so you can ask better questions.
