Areas We Serve

Areas We Serve

Why Does Water Pressure Drop Whenever Someone Flushes a Toilet?

Ever been in the middle of a nice hot shower and suddenly the water slows to a trickle because someone flushed the toilet? If you live in Bellevue, you’re definitely not the only one. We get calls about this all the time at 2 Sons Plumbing Bellevue, and while it’s annoying, it’s usually not a mystery. There are a handful of reasons why pressure dips—and a few good fixes to make sure it doesn’t keep happening.

Why Water Pressure Takes a Hit

In a perfect world, your plumbing system should be able to handle more than one thing at a time. If it doesn’t, here’s what’s probably going on:

Old Pipes

Lots of older Bellevue homes still have galvanized pipes. Over time, the inside rusts and fills with buildup. That narrows the pipe, so when the toilet fills up, there’s just not enough water left to keep the shower steady.

Small Supply Lines

Sometimes the pipes running to your fixtures are too small for today’s water use. Back when your house was built, the system may have worked fine—but with modern appliances and bigger households, undersized lines can’t keep up.

A Worn-Out Pressure Regulator

Homes on city water often have a regulator that controls incoming pressure. When it wears out or drifts out of adjustment, you’ll feel the difference the second someone flushes.

Things You Can Try Yourself

There are a few easy things you can do before calling us out:

Space things out. Avoid showers while the dishwasher or laundry is running.
Add a pressure-balancing shower valve. This keeps your shower steady even when other fixtures kick on.
Check your regulator. If you have one, it might just need a quick adjustment.

These aren’t long-term fixes, but they can make daily life a little easier.

When It’s Time to Call a Plumber

If every part of the house sees a big pressure drop whenever water is used, it’s worth having a pro take a look. The problem usually comes down to old pipes or a failing regulator.

At 2 Sons Plumbing Bellevue, we’ll test your pressure, check the regulator, and see if your supply lines are big enough for your household. Depending on what we find, the fix might be:

Replacing the pressure regulator ($750–$1,200): Keeps water flow balanced throughout the house.
Installing a new shower valve ($650–$1,700): Keeps your shower comfortable even when someone flushes.
Repiping: If the whole system is outdated, fresh pipes can solve the problem for good.

Steady Water Pressure = Less Stress

Nobody likes playing “shower roulette” every time a toilet flushes. With the right fix, you can stop the pressure drops and enjoy steady water all over your home.

At 2 Sons Plumbing Bellevue, we’ve helped homeowners across the area get reliable water pressure back. Call us today at (206) 487-1757. We’ll find the cause, walk you through the solution, and make sure your Bellevue home has the water pressure it should.

2 Sons Plumbing, Electrical, Heating & Air

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Maria Kute

23:01 18 Nov 25

Thank you, Bob, for your professional, courteous, and kind service! My downstairs tub was running with high pressure due to some worn out stems. Bob was thorough—but unfortunately our fixtures are quite old, and he didn’t have appropriate replacements available the first day. However, they were able to find the appropriate stems for our tub and fixed the leak right away day 2. I cannot speak highly enough about how grateful I am for the way 2 Sons accommodated my schedule when they needed to return with the appropriate fixtures. The technician was a genuine joy to work with—and I appreciate the quick follow up and turn around. I also appreciate the way Bob walked me through the process and double checked for leaks.

Maria Kute

23:01 18 Nov 25

Evan Rose

16:17 18 Nov 25

We had a great experience. Brandon and Chris were very polite and professional. We had a massive leak under a toilet and they came and fixed it on a Saturday. They were very timely and hardworking. Ethan was another who was also very polite and professional. Pricing was also very manageable for the extent of the problem we had. I would highly recommend.

Evan Rose

16:17 18 Nov 25

YuliyaG

22:06 14 Nov 25

I had a great experience with 2Sons Plumbing. Communication was on point from start to finish. Dave arrived on time, was very friendly, and knowledgeable. He also gave me a helpful heads-up about our heater and offered great advice. I really appreciate the professionalism and will definitely use them again!

YuliyaG

22:06 14 Nov 25

Brandy Przybylak

19:28 05 Nov 25

We really enjoyed our experience with 2 Sons. We had an emergency that had water all over our kitchen and basement. They were able to send someone out later in the evening for us after several other companies either cancelled on us or said they couldn't come until the next day. Our technician/plumber Riley was great to work with - friendly, quick, and effective! They even gave us a call back a few days later to check in on our experience and to answer some extra questions we had. Highly recommend!

Brandy Przybylak

19:28 05 Nov 25

Carol Wong

19:21 04 Nov 25

I have not decided to go with 2 Sons for the plumbing issues I have yet. However, I am very impressed by the technician, Guy, who came for the appointment. He was professional, friendly, knowledgeable, courteous, and thorough. I told him that I was just getting a quote and not ready to commit to do the repair right away. He was very understanding. I have a clogged kitchen sink, disconnected washer hose causing water damage, and likely a disconnected pipe behind the wall. He explained the steps I need to take before he can help for all three issues. Like I should hire the restoration company to repair the water damage before reconnecting the pipes. He also helped to take pictures and referred me to a restoration company for the jobs outside of his scope. Before he left, he measured the water pressure to make sure the pressure is within a normal range. Just to make sure the water is not putting too much pressure on the fixtures resulting leaks. It was definitely a surprisingly pleasant and thorough experience with Guy.

Carol Wong

19:21 04 Nov 25

Joanne Chan

01:00 31 Oct 25

Excellent service from 2 Sons Plumbing – highly recommended!

We recently had 2 Sons Plumbing come out to fix several issues at our place. We couldn’t be happier with the results. Marcos and Chris were absolutely fantastic — professional, knowledgeable, and very thorough in their work. Every single job was done with precision and care.

Marcos and Chris took the time to explain what they were doing, answered all our questions patiently, and made sure everything was up to code and functioning perfectly before they left. They worked efficiently, left the area spotless.

It’s rare to find such reliable, honest, and detail-oriented professionals these days. I wouldn’t hesitate to recommend them to my friends and neighbors.

Joanne Chan

01:00 31 Oct 25

Jurusha Emerson

16:11 28 Oct 25

I called 2 Sons Plumbing and was able to get them to come out to the house the very next day. The over the phone customer service were very personable and friendly. On the day of my appointment, Bob was the one sent to our house to fix our kitchen faucet. Bob was extremely friendly and helpful in fixing my faucet. He was very considerate and quick with his work. I did not feel like I was being taken advantage of or overpriced as far as how much they were charging. Bob was always transparent with the cost and also trying to find the most cost-effective way to accomplish what needed to get done? I would recommend 2 Sons plumbing to anyone who needs plumbing service. 2 Sons plumbing has a gem for an employee (Bob). If I were to call 2 Sons plumbing again for service, I would definitely want to request Bob as my priority person.
Thankyou so much

Jurusha Emerson

16:11 28 Oct 25

Mackenzie Maynes

02:22 28 Oct 25

After the recent power outage I discovered that my combi-boiler went on the fritz, meaning no hot water and no heat in my home—a very chilly situation for Seattle fall. 2 Son’s was so friendly and able to send out Adam same-day which was a huge relief! Adam quickly assed the issue, fixed it and provided a thorough explanation of what he did to get the system up and running again (which I deeply appreciated). I am thoroughly impressed by his knowledge of these units; turns out the pressure reducing valve on my machine also needs to be replaced, which explains why my water pressure has always been a bit funky between hot and cold. Adam provided an affordable proposal for a future repair to my unit for optimal functioning. Would absolutely recommend Adam and 2 Sons!

Mackenzie Maynes

02:22 28 Oct 25

Amy J

01:15 28 Oct 25

Had a great experience with 2 Sons Plumbing, Heating & Air. Their scheduling system was smooth — I got a call when Carey was assigned, could track his arrival, and everything ran on time. Carey was fantastic! He inspected the garbage disposal, coordinated with my property manager for approval, and quickly installed the new system. He was respectful, efficient, and made sure everything worked perfectly. Really appreciated his help!

Amy J

01:15 28 Oct 25

Oaktree President

22:17 24 Oct 25

Our house decided to replace our own toilet, but we got stuck halfway through because we didn’t have the right tools and accidentally broke an anchor bolt. I called 2 Sons Plumbing, and they showed up within an hour to help us out. Derek, our plumber, was super friendly, explained everything clearly, and got the job done quickly and professionally. Excellent service all around—highly recommend!

Oaktree President

22:17 24 Oct 25