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Areas We Serve

Why Do I Hear My Pipes Knocking at Night?

It’s late, the house is quiet, and then come the sounds—bang, tap, knock. You hear it again. The noise seems to come from inside the walls, making you wonder what’s going on with the plumbing. If this happens in your Seattle home, don’t worry—you’re not alone.

At 2 Sons Plumbing Seattle, we get calls all the time from homeowners kept awake by noisy pipes. The good news? That knocking sound usually has a simple explanation, and with the right fix, you can enjoy quiet nights again.

Why Pipes Make Noise in the First Place

Most of the time, knocking pipes happen due to one of two causes:

Thermal expansion – When hot water runs, the pipes expand and can rub or tap against wood framing, creating popping or knocking noises.
Loose supports – Pipes that aren’t secured tightly can shift when water moves through them, producing sound.

While the noises don’t always signal a major issue, ignoring them can add stress to your plumbing over time.

What You Can Try on Your Own

Here are a few things homeowners can check before calling a plumber:

Inspect pipe hangers or straps – Pipes should be secure, but not squeezed tightly.
Add foam insulation – This cushions the pipes and reduces contact with framing.
Flush your water heater – Sediment buildup can contribute to pressure changes and noise.

These simple steps often reduce or eliminate the knocking. However, if the sounds keep returning, it may be a sign that a professional inspection is needed.

When the Noise Is a Red Flag

Some knocking noises indicate a more serious problem. Be cautious if:

The knocking comes with low water pressure
You notice leaks near fittings or valves
The banging happens constantly, even after DIY efforts

Issues like water hammer, pressure irregularities, or worn-out valves may be to blame. In these cases, a licensed plumber should step in before the issue becomes more costly.

Typical Repair Costs in Seattle

The cost depends on the cause of the noise. On average, homeowners can expect:

Securing loose pipes: $150–$350
Installing an expansion tank: $400–$800

While these repairs require a professional, the long-term benefits help prevent more serious plumbing issues down the road.

Let 2 Sons Plumbing Seattle Bring Back the Quiet

Knocking pipes can be stressful—especially when they interrupt your sleep. The fix doesn’t have to be complicated. With the right help, you can eliminate the noise and protect your home’s plumbing at the same time.

Homeowners across Seattle rely on 2 Sons Plumbing because we respond quickly, explain things clearly, and get the job done right.

If pipe knocking is keeping you up at night, call 2 Sons Plumbing Seattle at (206) 487-1757. We’ll find the cause, make the proper repair, and restore the peace and quiet you deserve.

2 Sons Plumbing, Electrical, Heating & Air

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Based on 3536 reviews

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Ashley Arata

23:22 29 Jan 26

Carey and Micah came out on short notice when our tankless water heater started leaking unexpectedly. They were able to provide an extremely competitive quote on site and schedule us for installation the next day. We had some other pre-scheduled contractors in our home when they did the installation and they were extremely professional and courteous in making space for them to share space. I also appreciate how they cleaned up after work was completed. Overall wonderful guys and our second time using 2 Sons (once prior was to have a sewer line cleared) and we'd absolutely use them again. Thanks, Micah & Carey for the work!

Ashley Arata

23:22 29 Jan 26

Johnnie Williams

06:40 15 Jan 26

I want to start by saying that Jeff and the rest of the plumbing team are absolutely great. They are very knowledgeable, professional, and clearly know what they’re doing. The quality of their work is solid, and I never felt like I was dealing with people who didn’t understand their craft.

That said, the pricing is extremely high. I completely understand paying for quality and expertise, but the cost made it hard to move forward with them for future work. If their prices were more reasonable, they would 100% be the company I would use every time.

So if budget is not a concern, you’ll likely be very happy with them. But for those of us who have to balance quality with affordability, the pricing is something to seriously consider.

Johnnie Williams

06:40 15 Jan 26

Kizmit

01:40 03 Jan 26

I had a kitchen sink that started draining very slowly. Scheduling with 2 Sons was quick and easy. The technician arrived on time and was polite and friendly. Unfortunately, he was unfamiliar with the pipe configuration in my condo building and told me he was unable to get the cable through. He then provided me a written estimate for over $1600 to reconfigure the pipes. He stated the drain could not be cleared until that work was done. I was charged over $500 even though he was unable to do any work (got the cable down the pipe less than 5 feet before he gave up.) I called another plumber who came out a few days later and was able to use the cable to clear the drain (exactly what the plumber from 2 Sons said could not be done). I have emailed 2 Sons three times, explaining my concern and requesting a refund of the fee I paid, but am having difficulty getting anyone to respond to me. Overall, a very frustrating experience. I cannot recommend them based on this experience and lack of response.

Kizmit

01:40 03 Jan 26

Deann Minamino

22:05 02 Jan 26

We have used 2 Sons Plumbing quite a few times now and have never been disappointed! Courteous, professional, knowledgeable and efficient describes everyone from the office to the field teams! One of their team members, while here installing a sink fixture, overheard an estimate we were getting from a visiting sales rep for a project. Their team member (Carey) offered that the estimate was way over priced (by over $20k). We had 2 Sons price it out for us and they came in $23k less. We have a couple planned projects upcoming and plan to use them for that as well as any unexpected issues that arise. Just this week, they dispatched a team on NYE as our water heater broke. Once again, good price, courteous, professional and efficient! I/we are so pleased to have found this company! We highly recommend them! (NOTE/FYI: I, the posting party, copied this from my Yelp Review)

Deann Minamino

22:05 02 Jan 26

Ashley Dunn

21:37 01 Jan 26

Justin and Bryce were swift and thorough when we experienced an emergency leak in our daylight basement. They quickly identified the problem as a leaking water heater, provided a quote, and completed the work within just a few hours. The job included draining the old water heater, removing and properly disposing of it, and supplying and installing a brand-new unit. We are incredibly grateful that they came out on New Year’s Eve and ensured we didn’t start 2026 without running water. They also offered a great recommendation for addressing separate water damage caused by another issue. Highly appreciated and highly recommended

Ashley Dunn

21:37 01 Jan 26

Benjamin Grossman

05:40 30 Dec 25

Huge props to Adam. We had been trying to replace our kitchen sink ourselves but ran into some issues, so we called for help. They were able to come out the very same day, which was a huge relief. We needed a new faucet installation, a separate hot water faucet, and water tank set up.

Adam was fantastic. He fixed our kitchen sink and even helped with a stubborn screw we could not get undone (I spent 4 hours myself before trying to get it out) , all with incredible patience and friendliness. He explained everything he was doing clearly, which made the whole process easy to understand and feel confident about. The new installation looks fantastic. Will definitely use them again.

Benjamin Grossman

05:40 30 Dec 25

Heejae Yang

02:27 30 Dec 25

Great service for people who hate money

This is a wonderful company to repair your plumbing issues, including storm drains and sewer lines—ONLY if you have the disposable income of a tech bro or sis. I don't.
I called because the storm drain receiving my downspout was clogged. It was adjacent to work they have done before. Without even coming to the site, a technician diagnosed a total failure over the phone. Their solution? Demolish the concrete, access and remove the P-trap, and redo the entire install for a "discounted" manager promo of $4,000.
I ended up fixing the issue in 5 minutes with a Shop-Vac. Total cost: $0.
I’ve used them for a sewer line repair before and now realize I likely funded their entire holiday party. Why fix a drain for free when you can pay $4,000 to have your walkway ripped up? This is the team for you if your budget is infinite and your patience for common sense is zero.

UPDATE: A real pro checks for a simple clog before recommending a sledgehammer. We all know they were looking for a payday.

Heejae Yang

02:27 30 Dec 25

Maggie McNish

00:43 30 Dec 25

Adam came to my house and gave excellent service and worked very efficiently. He was incredibly professional and personable and kind. He educated me on my plumbing situation so that I’m better equipped to prevent issues in the future and to preserve integrity of items and appliances I use and in a way easy for me to understand. I hope every experience for every customer with 2 Sons goes this way. Everyone I’ve had come to my house with 2 Sons has been great — competent, kind, professional, and transparent. Adam was terrific.

Maggie McNish

00:43 30 Dec 25

Matthew Horak

03:56 25 Dec 25

Justin and Bryce responded to a same day house call on December 9 when we found water seeping between the wall and floor of our garage laundry area. I cannot rate their service highly enough. They arrived around 5pm and stayed until after 8:30 to finish the job the same day. I waited to submit a review because other work we've had done was done to last a few days -- just enough time to get a good review. Justin and Bryce's work has definitely held up. It was unclear where the leak was coming from, but they spent a.long time investigating, including in the crawl space under the house, to find the right place in the wall to open up. They opened up only about 2 feet of wall and hit the leak exactly. They fixed it quickly and permanently. They are very professional and efficient. We are extremely happy and will definitely call 2 Sons first for any future needs. Thank you!

Matthew Horak

03:56 25 Dec 25

Melissah Watts

02:23 12 Dec 25

I had a wicked combo of 50 yr old bathtub faucets ( the hot water completely frozen in the “on” position) and a 13 year old hot water heater …. Yep, on Saturday … 2 Sons sent Carey out on Sunday and he advised me to wait until Monday when he could really solve my problem with high quality hardware and a new hot water heater! Carey came out Monday with Micah , beautiful copper pipes, a new hot water heater and a modern bathtub faucet. In 5 hours I had a new bathtub faucet and a new hot water heater. On top of really good craftsmanship , they respected and protected my existing tub/ toilet / sink. Thanks for a job well done!! M & M Watts

Melissah Watts

02:23 12 Dec 25