water heater services

Fast water heater repair, replacement & tankless installs across Seattle

Same-day appointments · ★★★★★ 5-Star Google Reviews
Licensed • Bonded • Insured • Residential & Commercial

Water heater services available - call or text now

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LEAKING OR NO HOT WATER?

We repair and replace tank and tankless water heaters across Seattle, and we can often get you scheduled the same or next day. Tell us what’s going on and we’ll call you back with a free estimate.

Free estimates with clear, upfront pricing
Gas, electric, tankless & combi systems installed
Bradford White & Navien – or your preferred brand
Permits handled and your old unit hauled away
Licensed, bonded & insured local plumbers

“When my water heater started leaking the other day, I immediately reached out to Knockout, and they were able to get me scheduled the next day!”
– Mindy M., Google review ★★★★★

WATER HEATER INSTALLATION & REPLACEMENT IN SEATTLE

Need a new water heater or replacing an existing system? Knockout Plumbing & Mechanical provides free estimates for professional water heater installation and replacement throughout the greater Seattle area. Our licensed plumbers install gas, electric, tankless, and combi systems with reliable, code-compliant workmanship.

Not sure which water heater is right for your home? We’ll help you compare your options and choose a system that fits your household, space, and hot water needs.

✅ Tankless Water Heaters

High-efficiency, on-demand hot water without the space required for a traditional tank.

✅ Gas Water Heaters

Fast recovery times and consistent heat—ideal for busy households using natural gas or propane.

✅ Electric Water Heaters

A cost-effective, compact option for smaller homes or properties without gas service.

✅ Combi-Boilers

Combine home heating and hot water into one efficient system—perfect for maximizing space.

WHY CHOOSE KNOCKOUT FOR WATER HEATER REPLACEMENT?

From straightforward replacements to new water heater installations, our licensed plumbers make the process simple. We’ll help you choose the right system for your home, provide clear upfront pricing, handle required permits, professionally install your new water heater, and remove your old unit..

📞 Have questions or need a quote? Call or text us at (206) 858-2211 for advice or a custom quote from one of our licensed technicians.

FAQ – HOT WATER HEATERS

How long does it take to replace a water heater?
Most standard water heater installs are completed within 2–4 hours, depending on access and plumbing conditions.

Can you upgrade me to a tankless system?
Absolutely! We’ll assess your current setup and help you switch to a space-saving tankless unit if it’s a good fit.

Do I need a permit for a new water heater?
Permit requirements vary by location and project. We can determine what’s required for your installation and handle the permitting process when needed.

What brands do you install?
We typically install trusted brands like Bradford White and Navien, but we’re happy to work with your preferred model too.

What size water heater do I need?
This depends on your household size and hot water usage. We’ll help you select the right gallon size or BTU rating.

Water heater installations are completed by licensed plumbing professionals in accordance with applicable local codes.

    
 
 
       Posted on Google  
    Justin Gerardy 
 
 
 
 Trustindex verifies that the original source of the review is Google. As a restaurant owner in Seattle, I tend to find it infuriating when tradespeople over charge. It’s a real problem in this city. Knockout was fair and fast. Can’t say how much I appreciate it. I’ll be back for sure.
  
 
      Posted on Google  
    Margot Potts 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zack and his crew were able to come within a couple days of calling and resolved my issue within minutes. They were very friendly and generous - highly recommend!
  
 
      Posted on Google  
    Veronica Seifner 
 
 
 
 Trustindex verifies that the original source of the review is Google. Knockout was great to work with - very courteous, responsive, and fair pricing. Zach came out to cap off a gas line for an appliance we switched to electric. The option was to do it from the inside or from the outside and remove the dedicated pipe altogether. Zach gave reasonable pricing (checked with two other companies) and was able to get the job done right away with expertise and professionalism. Knockout will be our top-choice, first-call for any future pluming needs in our home.
  
 
      Posted on Google  
    Mindy Martin 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent experience. I was considering replacing my water heater back in the spring and Knockout was one of the companies I shortlisted to talk to. Ultimately I decided to wait on replacement, but Knockout was definitely at the top of my list. When my water heater started leaking the other day, I immediately reached out to Knockout, and they were able to get me scheduled the next day! I was given the choice between Bradford White and AOS. Zach came out and did a fantastic job. Friendly but professional; quick and efficient but thorough. Knockout respected the quote I was given a few months back which was very competitive. I strongly recommend this company!
  
 
      Posted on Google  
    rozap _ 
 
 
 
 Trustindex verifies that the original source of the review is Google. I asked these guys about hydrojetting our old sewer line that would occasionally get clogged. Zach showed up and looked at the situation, and after chatting for a bit he figured I could DIY it so I would know how to do it rather than paying every time it happeened. So he showed me a fitting for my pressure washer I could get, and described what to do. I did all that and it worked great, and I saved $850 that it would have cost, and then I knew how to do it going forward. They didn't even charge me. They're super honest guys with a lot of integrity. Definitely recommend them.
  
 
      Posted on Google  
    Jason Franklin 
 
 
 
 Trustindex verifies that the original source of the review is Google. Colin and his team have completed 2 projects for us and is always very helpful and informative in his diagnosis and explaining his course of action. I highly recommend him and Knock out Plumbing for all your plumbing needs.
  
 
      Posted on Google  
    Michael Johnson 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zach has done a number of plumbing jobs for us over the years ranging from large bathroom additions to smaller repairs, every time they've been top quality. I highly recommend Knockout!
  
 
      Posted on Google  
    Simone 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zach is a consummate professional. He was thorough, timely, efficient, personable, and diligent. He returned the next day after the job to place a cover on a part, which is something my partner & I wouldn’t have known. Clearly, he has integrity, which in my book is paramount. We emphatically would not recommend anyone else, but him and his team for plumbing jobs. We were beyond pleased with Zach’s skill and caliber. 20/10 ⭐️
  
 
      Posted on Google  
    Evan Wiederspan 
 
 
 
 Trustindex verifies that the original source of the review is Google. Zack and his crew replaced my kitchen sink drain after it started leaking. I was really happy with the price, and the speed and quality of their work. It was also easy to get a quote and schedule over the phone. I would definitely hire Knockout Plumbing again in the future!