Intro

On many jobs, you hear pipes bang when a valve snaps shut. It’s annoying. It can also damage pipes and valves. A very smart plumber shared a trick! It stops water hammer fast, without guesswork. Here’s the simple plan: check pressure, strap the lines, and add arrestors near quick-closing valves. In most homes, you can do this in 30–45 minutes. I’ll show you the tools, the steps, and when to upgrade. You’ll see clear measurements, timeframes, and pricing tips you can use today.

Quick Answer

A very smart plumber shared a trick: fix water hammer by first checking static pressure (target 50–60 psi), then strapping loose runs, and adding water hammer arrestors within 3–6 inches of quick-closing valves (washers, dishwashers, ice makers). This takes about 30–45 minutes and usually ends the banging for good.

Table of Contents

• What Is Water Hammer And Why It Matters
• A Very Smart Plumber Shared a Trick: The Fast Diagnosis
• Tools And Materials You’ll Need
• A Very Smart Plumber Shared a Trick: Step-By-Step Fix
• Testing, Timeframes, And When To Upgrade
• Pricing, Communication, And Simple Proposal Tips
• FAQ
• Conclusion

Key Takeaways

• Check static pressure first. Aim for 50–60 psi; over 80 psi is a red flag.
• Strap copper every 6–8 ft and PEX every 3–4 ft to cut vibration.
• Place arrestors 3–6 inches from quick-closing valves for best results.
• Most fixes take 30–45 minutes and use common 1/2-inch fittings.
• Adjust PRV in 1/4-turn steps, then re-test after 10 minutes.

What Is Water Hammer And Why It Matters

When a valve closes fast, water stops suddenly. That pressure spike slams pipes and fittings. You hear it as a bang or rattle. It’s common with washing machines, dishwashers, and ice makers.

Why care? Repeated hammer can crack solder joints, stress PEX fittings, and shorten valve life. In general, anything above 80 psi makes it worse. Keeping supply pressure near 50–60 psi prevents most issues.

A Very Smart Plumber Shared a Trick: The Fast Diagnosis

A very smart plumber shared a trick that starts with simple checks. Don’t rip walls or replace valves yet. Confirm the basics in this order:

1. Measure static pressure. Use a gauge on an outside spigot or laundry tap. With no water running, you want 50–60 psi. If you see 75–90 psi, plan to adjust the pressure reducing valve (PRV) or add one.
2. Identify the noisy fixtures. It’s usually a washer, dishwasher, or ice maker. Those close in under 1 second.
3. Check pipe support. Long, loose runs act like a drum. Look for spans over 6–8 ft in copper or 3–4 ft in PEX.
4. Look at valve locations. The closer an arrestor is to the valve (3–6 inches), the better it absorbs the hit.

This quick path saves you 1–2 hours on most service calls.

Tools And Materials You’ll Need

• Pressure gauge with 3/4-inch hose thread
• Arrestors sized for 1/2-inch or 3/4-inch lines (AA/AAA type)
• Pipe straps: copper every 6–8 ft; PEX every 3–4 ft
• Drill/driver and screws for straps
• Adjustable wrench and Teflon tape
• For PRV: hex key or flat screwdriver, plus a marker to track 1/4-turn adjustments

A Very Smart Plumber Shared a Trick: Step-By-Step Fix

Follow these steps. They’re fast, clean, and proven on site.

1. Confirm Pressure (5 minutes)

   • Attach the gauge to a hose bibb. No water running.
   • Read static pressure. Target 50–60 psi. If it’s above 80 psi, plan a PRV adjustment or replacement.

2. Adjust PRV If Needed (10–15 minutes)

   • Mark the current setting. Turn the screw/bolt in 1/4-turn steps.
   • After each change, run water for 30 seconds, then recheck static pressure.
   • Settle at 55–60 psi. Wait 10 minutes. Re-test a quick-close valve. Bang gone? Move on. Still there? Keep going.

3. Strap Loose Runs (10 minutes)

   • Add cushioned straps. Copper every 6–8 ft; PEX every 3–4 ft.
   • Pay attention to vertical runs. Strap within 12–18 inches of elbows and tees.

4. Add Arrestors Near Valves (10–15 minutes)

   • Install arrestors 3–6 inches from the problem valve. Use 1/2-inch or 3/4-inch fittings to match the line.
   • Washing machine boxes: many accept screw-on arrestors. Kitchen sink lines: use angle-stop arrestors.
   • Keep them upright if possible. Follow manufacturer directions.

5. Final Test (5 minutes)

   • Close the suspect valve fast 3 times. Listen.
   • If you still hear a light tap, add a strap or a second arrestor on the hot line.

This is the core of “A very smart plumber shared a trick!”—pressure, support, arrestors—done in under 45 minutes on most jobs.

Testing, Timeframes, And When To Upgrade

• Timeframe: Most houses are done in 30–45 minutes. Multi-story runs can take 60–90 minutes.
• Re-test the next day: Ask the client to run the washer and dishwasher once. Light sounds may settle as air moves.
• When to upgrade:
  • No PRV present and static pressure stays 75–90 psi. Add a PRV.
  • Old air chambers keep filling with water. Replace with sealed arrestors.
  • Multiple long branches hammer. Add a main-line arrestor near the manifold.
• Cold climates: Insulate arrestors on exterior walls to prevent condensation.

Pricing, Communication, And Simple Proposal Tips

Clients want fast answers. Explain the plan in plain language: “We’ll set pressure to 55–60 psi, strap loose lines every 6–8 feet, and add arrestors 3–6 inches from the valves. You’ll stop the banging today.” That level of detail builds trust.

On site, snap 2–3 photos and record a 20–30 second note. Tools like Donizo let you turn voice, text, and photos into a clean, branded proposal in minutes, get an e-signature, and convert it to an invoice with one click. This reduces back-and-forth and helps you close while you’re still at the sink.

Internal linking ideas for your website:

• If you’re also looking to streamline professional proposals, our guide covers proven templates.
• For contractors dealing with scope changes, see our article on managing change orders.
• This pairs well with understanding invoice templates that save time.

FAQ

What causes water hammer in the first place?

A fast-closing valve stops moving water in an instant. That pressure spike hits elbows and tees, and the pipe shakes. High static pressure, long unsupported runs, and lack of arrestors make it worse.

Where should I install water hammer arrestors?

As close to the quick-closing valve as possible, ideally 3–6 inches away. For washers, use arrestors at the box. For dishwashers and ice makers, add them at the angle stop or inline near the appliance.

Is lowering pressure to 50–60 psi safe?

Yes. Most fixtures and codes accept 50–60 psi as ideal. In general, anything above 80 psi is considered excessive and increases wear on valves and hoses.

Do air chambers still work?

Old air chambers often waterlog and stop working. You can drain the system to recharge them, but the fix may not last. Sealed, spring-loaded arrestors are reliable and require no recharging.

How long does the fix take and what does it cost?

Most service calls take 30–45 minutes. Time increases with multi-story runs or hard-to-reach valves. Many contractors price this as a small service package that includes pressure check, strapping, and two arrestors.

Conclusion

Water hammer is simple to beat when you follow a clear plan. Set pressure to 55–60 psi, strap long runs, and add arrestors within 3–6 inches of quick-closing valves. That’s the heart of “A very smart plumber shared a trick!” and it works.

Next steps:

1. Add a pressure gauge to your kit and test every call.
2. Stock 1/2-inch and 3/4-inch arrestors and cushioned straps.
3. Capture photos and details, then send a same-day proposal with tools like Donizo to lock in approval fast.

Do this on your next noisy call. You’ll quiet the lines and impress the client.