How much does it cost to fix a pinhole leak in a copper supply line?

Where the money goes

On the DIY side, the parts are cheap. A push-fit repair coupling runs $12 to $22. A decent pipe cutter is $15 to $30, and you keep it. Emery cloth and a rag round it out.

If you already own the cutter, you're under $40 in materials.

On the pro side, the fitting is a rounding error. You're paying for the plumber's time and truck.

Expect a service call or trip fee of $75 to $150 just to show up. Labor typically runs $120 to $200 an hour, with a one-hour minimum common.

A simple, exposed pipe repair might be $150 on the low end. Add a hidden pipe behind drywall, a hard shut-off, or after-hours emergency rates and you're at $500 or more.

Cutting into a finished wall or ceiling adds drywall repair on top, usually $150 to $400 depending on who patches it.

• Push-fit repair coupling: $12-$22
• Pipe cutter (one-time): $15-$30
• Plumber trip/service fee: $75-$150
• Plumber labor: $120-$200/hr, 1-hr minimum typical
• Drywall or ceiling patch after access: $150-$400

How we built these numbers

The cost ranges here reflect 2026 US pricing for a single pinhole repair on a residential copper supply line.

DIY figures assume common retail prices for push-fit fittings and basic tools, with the pipe accessible and no wall repair needed.

Pro figures blend typical service-call fees, hourly labor, and the one-hour minimums most plumbers charge, across both simple exposed repairs and harder hidden ones.

Regional labor varies widely. Dense metros and emergency after-hours calls push toward the top of the range, while rural and standard business hours land lower.

These are planning numbers, not a quote. Get a written estimate before any pro work, and confirm whether drywall repair is included or separate.

What a pinhole leak repair actually costs

That covers a push-fit repair coupling, a pipe cutter if you don't own one, and a few odds and ends.

A licensed plumber runs $150–$500 for the same job. Most of that is the trip fee and minimum labor, not the fitting.

The repair itself is small. What drives the price is access, how dry the pipe is, and whether the plumber has to cut into a finished wall or ceiling to reach it.

Here's the part people miss: the cost of the patch is almost never the real decision. The real question is whether one pinhole means more are coming.

Why copper develops pinholes

Pinholes come from the inside out. The water chemistry, not something outside the pipe, is usually to blame.

The most common driver is pitting corrosion. Certain water (low pH, high chloramine, high oxygen) attacks copper in tiny concentrated spots until a hole punches through. You'll see a green or blue-green stain around the leak.

High water velocity is the next suspect. Water moving too fast erodes the pipe wall, especially at the outside of elbows. Undersized pipe or a failed pressure regulator makes it worse.

Old soldering flux is a quieter cause. Acidic flux that never got flushed keeps eating the pipe for years, and the leak shows up just downstream of an old joint.

Then there's electrolysis, where copper touching steel or a bare ground wire sets up a tiny current that corrodes the contact point. And freeze cracks, which mimic a pinhole but come from a hairline split.

If you can tell which cause you're dealing with, you'll know whether a spot repair is enough or whether the whole system is on borrowed time.

Step by step: from leak to fixed

Start by stopping the water and the pressure. Everything else is easier on a drained, dry pipe.

Shut the main valve or the nearest isolation valve. Open the lowest faucet in the house to break the vacuum and drain the line.

Now find the exact hole. Wipe the pipe dry and watch for the first bead of water to reform. On a thin drip, this can take a minute.

Clean the pipe. Wire-brush or sand a few inches on each side of the leak until the copper is bright. Any repair, push-fit or soldered, needs clean metal.

Cut out the failed section. A slim pipe cutter works in tight spots. Cut back at least an inch past any visible pitting or discoloration.

Install your repair. For DIY, a push-fit slip coupling is the simplest: push it onto both cut ends and you're done. Deburr the pipe ends first so you don't shred the internal O-ring.

Restore water slowly. Crack the main open partway, watch the repair, then bring it up to full pressure. Give it 15 minutes and check again.

• Tools for DIY: pipe cutter, emery cloth or fitting brush, push-fit coupling, rag, flashlight
• Skip soldering unless the pipe is bone dry and you've done it before
• Keep a bucket and towels staged under the work area

Should you DIY this one?

This is one of the more DIY-friendly plumbing repairs, thanks to push-fit fittings. No torch, no flux, no fire risk. If the pipe is exposed in a basement or crawlspace, most handy homeowners can handle it in under an hour.

Do it yourself if the leak is accessible, the pipe is otherwise sound, and you can cut and deburr copper cleanly.

Call a pro if the pipe is buried in a wall or slab, if you find multiple pinholes, or if you'd have to solder in a tight, flammable spot.

Also call a pro if the leak is on the line feeding your whole house before any shutoffs. Getting that wrong leaves you with no water and no easy fix.

One honest note: a push-fit repair inside a wall is fine, but if you're already opening drywall, it's worth having a plumber press or solder it for the long haul. Fittings you can't see should be the most reliable ones.

Can this wait?

Short answer: no, not really. A pinhole is a hole that's actively growing.

You can buy yourself a day or two with a clamp-on repair sleeve or epoxy putty. That's fine for getting through a weekend or waiting on a plumber.

What you can't do is ignore it. The corroded edge keeps eroding, and a drip becomes a stream. Inside a wall, that means mold in days and rotted framing in weeks.

The safest move is simple: shut the water off at the main until it's fixed. An inconvenient dry house beats a saturated one.

If the leak is over an electrical panel, near outlets, or dripping onto wiring, don't wait at all. Kill the power and shut the water now.

The 1980s-90s copper problem

If your house was plumbed with copper between roughly 1980 and 2000, take a first pinhole seriously.

A lot of copper installed in that era is now hitting the end of its usable life on aggressive water. Thirty to forty years of internal pitting adds up.

When one pinhole appears, the same conditions have thinned every other run in the house. Techs have seen homes get three or four separate leaks in a single year once the first one shows.

For those homes, do the math. Chasing pinholes at $400-plus a pop gets expensive fast. A whole-house PEX repipe usually runs $4,000 to $12,000 depending on size and access, and it ends the problem.

Before you commit either way, get the water tested. If pH is low or chloramine is high, patching copper just delays the next leak.