(209) 543-9300 info@unitedspasmfg.com

The Best In Spas

For 37 years, United Spas Manufacturing has delivered spa excellence — from our family to yours. Every spa and swim spa we design is built with your relaxation, comfort, and therapy in mind. Experience the difference of a high-quality, USA-built spa. Your journey to unmatched comfort starts here.

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Premium & Executive Spas

Swim Spas

Legacy Spas

Feel The Power

The Ultimate in Hydrotherapy

Designed With Vision

Provided With Care

Build Your Hot Tub or Swim Spa

Turn your dream spa into reality. Customize every detail and create the perfect hot tub or swim spa for your lifestyle. Contact your local United Spas dealer today! 

Hot Tub Spa by United Spas Mfg

The United Spa Difference

At United Spas, we don’t just build hot tubs—we build confidence. Every spa is proudly American-made and supported by our service team with over five years of hands-on experience per technician. From delivery to long-term care, our experts are ready, reliable, and always within reach. We ensure your spa arrives on time and in perfect condition, and our industry-leading warranty reflects the trust we place in every product we build. United Spas is more than a brand—it’s your assurance that support is always close and quality is never compromised.

Powered by Connection, Built on Innovation

We believe relaxation should be intuitive, indulgent, and built for real life. That’s why every United Spa is engineered with smart features that simplify maintenance and elevate your experience—so you can focus on what matters: enjoying the moment. Powered by precision craftsmanship, advanced technology, and a relentless drive to improve, we deliver performance you can feel and reliability you can trust—every single time.

 

You Design

United Spas has a variety of upgrades to make owning a spa a breeze! Our options are top of the line with every intention to benefit our consumers and their spa. We don’t offer any options without extensive testing and consumer feedback to insure that we are placing only the best at our customers fingertips. 

Woman luxuriating in a hot tub spa

Quality & Excellence

At United Spas Manufacturing, quality isn’t just a promise — it’s our legacy. For over 37 years, we’ve set the standard for excellence in the luxury hot tub industry.

How have we done it? By never compromising on quality. Every spa built to our specifications are crafted with precision, using only the highest-grade materials and time-tested techniques.

From the solid, hand-built frames and expertly engineered plumbing systems to the flawless electrical wiring and durable, multi-layer fiberglass shells, every detail is inspected, perfected, and approved before a spa leaves our facility.

When you choose United Spas, you’re choosing a spa built with unmatched attention to detail, reliability, and performance — because you deserve nothing less than the best.

Tim Kelly, owner of United Spas Mfg, best hot tub spas in Modesto

A Family Business Spanning Two Generations

For over 37 years, United Spas Manufacturing, LLC has been more than a business — it’s been a family tradition of quality, care, and innovation. Founded by Tim Senior and Nadine Kelly, what began as their dream has grown into a trusted name that families across the West Coast turn to for relaxation, comfort, and connection.

As the company has grown, one thing has never changed: our dedication to treating every customer like family. After decades of hard work, Tim and Nadine have proudly passed the torch to their son, Tim Kelly Jr., who carries forward the same values of integrity, service, and craftsmanship. At United Spas, our family is honored to continue serving your family for generations to come.

Tim Kelly Jr., owner of United Spas Mfg
Hot tub and spas

Our Spas

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Premium & Executive Spas

At United Spas Manufacturing, our Premium and Executive lines represent the pinnacle of luxury, innovation, and therapy. Every model is carefully designed with the latest upgrades in style, performance, and technology, delivering an unparalleled spa experience.

Whether you’re looking for soothing relaxation after a long day or powerful hydrotherapy for deep muscle relief, these spas are built to exceed expectations. Engineered for both family enjoyment and personal rejuvenation, our spas combine timeless craftsmanship with the modern features you deserve — making it no surprise when friends and family ask, “Where did you get your spa?”

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Swim Spas

Our Swim Spas are built for those who demand more than just relaxation. Designed with versatility in mind, these units deliver a perfect balance of low-impact exercise, full-body therapy, and stress-melting hydrotherapy.

Whether you want to swim for fitness, recover from a workout, or simply unwind, our swim spas are built with precision, durability, and performance that make them among the most respected and sought-after models in the industry.

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Certified Pre-Owned Spas

For those looking for exceptional value, our Certified Pre-Owned Spas are the perfect solution. These models — whether from our Legacy line or from our Premium collection — have been thoroughly inspected, refurbished, and tested by our expert technicians to meet our highest standards of quality.

Every Certified Pre-Owned Spa is built to stand the test of time, offering the same luxury, reliability, and comfort that United Spas has been known for over 37 years — at a price point that makes high-end relaxation more accessible. Our certified pre owned products come with a better warranty than most new spas on the market. That should give you the confidence most buyers dream of.

Happy Customers

“My hot tub got invaded by rats who chewed up water lines and my digital topside.  Was out of commission a couple weeks fixing the leaks and the owner Tim was able to hook me up quick with a new smart digital control and cover for a great price…”  Chief I., San Rafael

“Great place to buy a new or used spa.  After sale service is great too.  I had them come out 4 years after purchase for service and they were very accomodating, even though warranty had long since expired, and they had to travel about 100 miles.  Highly recommended.”  Steve G., Benicia, Ca

“My hot tub is awesome!  Just got it delivered yesterday.  Delivered it in a timely manner.  Good customer service.  Would highly recommend united spas to friends and family based upon my great experience.”  Robert D., San Francisco, Ca

I have owned a United Spas Hot tub for 6 1/2 years and it is still going strong!  I use it almost every day. I consider it more health care than entertainment, though it is fun to have, as well.  Luckily, I have not needed any servicing yet. I do keep the filters clean and check the water often.

Recently, I updated my home wifi and needed to reset my spa’s wifi controller.  I called in and was helped in such a speedy and friendly manner. A technician got on the phone and walked me through the update process.

After 6 1/2 years, my spa is running like new! I am so happy that I chose this company to work with. ”  Francis B., San Francisco, Ca

We bought our spa in 2021 and have loved it so much! The company was great from the start. Our visit to the showroom was low pressure and focused on educating how the spas are built and why they are durable and high quality. We wanted a spa that wouldn’t break down, that had good jets, and easy to maintain. They delivered and set up the spa then we had no issues until recently with a minor gasket leak. When we called them about the leak, they came out the next day to repair it and showed my husband what to do if it happened again. Their prices and warranty were excellent against the competitors and consistently great customer service. The quality of the spa is also fantastic and it has strong interchangeable jets which is the main feature we were interested in. We love our spa and expect to get many years out of it!”  A D., Lodi, Ca

I Called united spas for my yearly tune up and a service. Courtney picked up the phone and helped me arrange that. Matt came out and did tune and service. Both of these people were friendly, professional, helpful, very informative and educational. These two are the very type of employees that everyone business should have. I cannot say enough about the level of service I received. what a great experience because of these two. you have a customer for life. Thank you so much.”  Pete V., Modesto, Ca

We’ve had our spa for about four months and are loving it! Best investment I’ve made in a long time! When did have some trouble with keeping it clean and Tersea was so sweet and helpful. Problem solved. Squeaky clean.”  Natasha E., Pittsburg, Ca

United Spas was a very good choice for us, as we actually upgraded our spa with them.  The customer service with Eleanor is excellent and she calls annually to provide service checks.  When the techs  arrive, they are knowledgeable and very helpful each time they come.  I would recommend this spa company to anyone for purchasing a spa as well as the annual maintenance.  Very satisfied customer.”  Sistadi W., San Francisco, Ca

We bought a United Spas second hand from a private party. We called United Spas for help and advice and they treated us like we just spent $10,000 with them. Genuinely helpful, they’re a lesson in customer service and building relationships. Someday when we need a new one, guess where we’re going?:)”  Mark A., Ca

United Spas Mfg, a leader in hydrotherapy
United Spas Mfg - An A+ Better Business Bureau Rating
United Spas Mfg manufactures energy efficient hot tub spas.
United Spas Mfg's products are manufacture in California - Made in USA