4.9/5 — 2,000+ Five-Star Reviews
Reverse Osmosis System Installation
Bay Area's #1 Choice
United HVAC, Plumbing & Electrical provides reverse osmosis system installation for homes and rental units across the Bay Area. Our licensed plumbers assess your existing cold water line, test for hardness and contaminants, select the right unit for your household, and complete most installations in a single same-day visit.
- 25+ Years
- Licensed & Insured
- 24/7 Emergency
- No hidden costs
- Same-day service
- Fully licensed and insured
- 6000+ completed jobs
4.9/5 Rating
2,000+ Reviews
Licensed & Insured
CA Licensed
Same-Day Service
24/7 Emergency
25+ Years
Bay Area Experts
6,000+
Jobs Completed
Simple Process
How It Works
Call Us 24/7
Reach us anytime at
(408)539-6936.
Same-Day Dispatch
A licensed technician arrives at your home, often same day.
Diagnose & Fix
Upfront pricing before work begins. No hidden fees, ever.
100% Satisfaction
We stand behind every job with our satisfaction guarantee.
What Is a Reverse Osmosis System and What Does It Remove From Your Water?
A reverse osmosis system forces tap water through a semi-permeable membrane that filters out chlorine and chloramine byproducts, lead, PFAS, and dissolved solids down to a fraction of a micron. The result is water that tastes noticeably cleaner than tap or pitcher-filtered water. Most residential systems install under the kitchen sink and feed a dedicated drinking faucet.
How a Multi-Stage RO System Works
Water passes through three to five stages: a sediment pre-filter, one or two carbon filters targeting chlorine and chloramine, the RO membrane, and often a polishing carbon filter before the storage tank. Each stage removes a different contaminant class, which is why RO outperforms single-cartridge filters on total dissolved solids. Municipal water in San Jose, Sunnyvale, and Cupertino carries moderate hardness plus chloramine, a combination standard carbon filters don’t fully neutralize alone.
RO vs. Standard Water Filters: Key Differences
A pitcher or faucet filter uses activated carbon alone, which improves taste and odor but leaves behind dissolved minerals, most heavy metals, and many PFAS compounds. Reverse osmosis adds the membrane stage, removing a far broader range of contaminants and holding up more consistently over time. The tradeoff is that RO systems need a drain connection and periodic filter changes.
Signs You Need a Reverse Osmosis System Installed
You likely need reverse osmosis system installation if your tap water has a persistent chlorine or metallic taste, your household relies on bottled water daily, or a water test flagged lead, arsenic, or PFAS above your comfort level. These are the most common reasons Bay Area homeowners request installation over a basic filter.
Water Quality Issues Common in Bay Area Homes
SFPUC-supplied areas of the Peninsula, including parts of Menlo Park and Belmont, use chloramine as a secondary disinfectant, which resists standard carbon filtration more than chlorine alone and often carries a chemical smell. Older homes in Palo Alto and Los Gatos also see elevated lead readings from aging service lines, even when the municipal supply tests clean. Hard water is common throughout Saratoga and Campbell, which shortens RO membrane life if a pre-filter isn’t sized correctly.
When an Under-Sink Filter Is No Longer Enough
If you’ve replaced filter cartridges on schedule and the water still tastes off, or a household member needs lower-sodium or lower-TDS water, a carbon filter has reached its limit. At that point, reverse osmosis water filter installation is the practical next step, since it catches contaminants carbon-only systems aren’t built to handle.
Reverse Osmosis System Installation: How the Process Works
Installation starts with a water assessment to identify your incoming pressure, hardness, and any contaminants specific to your address, followed by system selection and a same-day install in most cases. A standard under-sink install typically takes two to three hours.
Pre-Installation Water Assessment and System Selection
Before recommending a unit, we test your cold water supply for pressure and hardness and review any available water quality report for your area. This determines whether you need a standard 3-stage system, an added pre-filter for hard water, or a whole house reverse osmosis system installation for water use beyond a single kitchen tap. Renters and condo owners in Sunnyvale and Milpitas often need a compact tank to fit cabinet space.
What Happens on Installation Day
Our plumber connects the system to your cold water supply line under the sink, installs a drain saddle on the existing drain pipe for wastewater discharge, and mounts the storage tank with pressure pre-set to the correct PSI. A dedicated RO faucet is installed at the counter, separate from your regular faucet. Before we leave, we run the first flush cycle and check every connection for leaks.
Reverse Osmosis System Installation Cost in the Bay Area
Reverse osmosis system installation cost in the Bay Area generally runs from the low hundreds for a basic under-sink unit to several thousand dollars for a whole-home system with pre-treatment. Your final price depends on system tier, existing plumbing access, and whether new supply or drain lines are needed.
Factors That Affect the Final Price
The biggest cost drivers are the number of filtration stages, whether your cabinet already has accessible cold water and drain lines, and whether extra pre-treatment is needed for hardness or sediment. A straightforward reverse osmosis filter installation with existing line access costs less than a whole house reverse osmosis system installation, which involves larger tanks and higher-capacity membranes.
Long-Term Savings on Bottled Water and Appliance Maintenance
A household that buys bottled water regularly typically recovers the installation cost within a year or two. Cleaner water at the tap also reduces scale buildup in coffee makers, ice makers, and water heaters, cutting appliance repair costs over time.
Why Bay Area Homeowners Choose United HVAC, Plumbing & Electrical for Reverse Osmosis System Installation
Homeowners choose United HVAC, Plumbing & Electrical because the company has installed water filtration systems across the Bay Area for over 25 years, carries full state licensing and insurance, and selects each system based on an actual water assessment rather than a standard package.
Licensed, Insured, and Local
Every plumber on our team holds a current California contractor license, and every installation is covered by liability insurance, so you aren’t personally on the hook if a connection fails after the visit. Being based locally also means a faster response if your system needs a follow-up adjustment.
25+ Years Improving Bay Area Water Quality
Our team has worked with the water conditions across San Jose, Cupertino, and Palo Alto for more than two decades, which shapes how we size pre-filters and set membrane specs for local hardness and chloramine levels. That history means fewer callbacks for premature membrane failure.
Custom System Selection Based on Your Water Conditions
We don’t install the same unit at every address. Selection is based on your measured water pressure, hardness, and known contaminants for your service area, so the filters you get match the water you actually have.
Ready to stop buying bottled water? Call United HVAC, Plumbing & Electrical at (408) 539-6936 — we’ll assess your under-sink space and install your RO system same-day.
100% Satisfaction Guarantee
If you're not completely satisfied with our work, we'll come back and make it right — free of charge. That's our promise to every customer.
Signs You Need Reverse Osmosis System Installation
- Cloudy or poor-tasting tap water
- Visible sediment or "floaties" in your drinking water
- Heavy chlorine smell or chemical aftertaste
- Desire for high-purity water without the plastic bottle waste
- Slow production of water from your existing filtration system
Why Choose United HVAC
- 25 years of experience
- Same-day service
- 1+ year warranty
- 6000+ completed jobs
- 0% interest financing and discounts
- Fully licensed and insured
- Well reviewed and highly trusted
- No hidden costs
- We work 365 days a year
Got Questions?
Frequently Asked Questions
A properly maintained RO system removes chlorine and chloramine byproducts, lead, arsenic, PFAS, and most dissolved solids that cause hard water buildup. It also reduces sodium and nitrates found in some municipal water reports. The exact removal rate depends on your membrane's rating and how recently the filters were changed.
Slow flow is usually caused by a clogged sediment pre-filter, a storage tank that's lost its air pressure, or a membrane nearing the end of its lifespan. Checking tank pressure first is the quickest fix, since it should sit around 7-8 PSI when the tank is empty. If pressure is fine and flow is still slow, the pre-filter or membrane likely needs replacement.
Pre-filters and carbon filters typically need replacement every 6 to 12 months, while the RO membrane usually lasts 2 to 3 years under normal Bay Area water conditions. Households with harder water should replace pre-filters closer to the 6-month mark to protect the membrane.
Older RO systems can discharge 3 to 4 gallons of wastewater per gallon of filtered water. Newer systems with a permeate pump or a tighter reject ratio bring that closer to 1:1, which is worth discussing during system selection.
Yes, reverse osmosis removes most dissolved minerals along with contaminants, including calcium and magnesium. Homeowners concerned about mineral content can add a remineralization cartridge as a final stage, reintroducing minerals without compromising contaminant removal.
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Reverse Osmosis System Installation
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Posted on Google Omied LeleTrustindex verifies that the original source of the review is Google. Pasha (technician) was very helpful. We had a clogged drain and were unable to clear it ourselves. He arrived and fixed the drain and was very clean and polite. Left everything as it was before he arrived. Highly recommend.Posted on Google Liang KatherineTrustindex verifies that the original source of the review is Google. Fantastic service! We really enjoyed working with United plumbingPosted on Google Natalia ShreveTrustindex verifies that the original source of the review is Google. Pasha was very professional he gave us a couple of options and finished the plumbing job very quicklyPosted on Google Just JaniceTrustindex verifies that the original source of the review is Google. As a busy homeowner I truly appreciate their ability to work around my schedule and needs. My garbage disposal recently died, and Neo was professional and offered my different options. He had the parts I needed and was able to complete the job quickly and cleanly.Posted on Google Chaozhong LianTrustindex verifies that the original source of the review is Google. I wholeheartedly recommend United HVAC, Plumbing & Electrical. I recently hired them to replace the original 1961 HVAC ductwork in my house, and they did a wonderful, extremely professional job. I am beyond satisfied with the results. You don't just have to take my word for it--I actually took pictures of their completed work, uploaded them to Google Gemini, and asked the AI to evaluate the installation. Even the AI praised their work, calling it a "top-tier, textbook installation"! (See the screenshots below). During the bidding process, I compared United with another company. United's quote was slightly higher, but choosing them was absolutely the best decision. Their program manager, Tim, was incredibly easy to work with. He quickly identified asbestos tape on my 1961 ducts and insisted we use a C-22 licensed abatement company to remove it safely and provide all the legal documentation for future reference. The other company offered a cheaper route by doing the removal themselves, but for something as dangerous as asbestos, doing it by the book is well worth the minor price difference. I also want to give a massive shoutout to Bair (Bayar) for his exceptional craftsmanship. He is easy-going, friendly, and really listened to all of my concerns. He provided great recommendations on how the new ductwork should be organized, and actually used a machine to fine-tune and balance the air pressure throughout the house. To top it all off, he even carefully reorganized the insulation in my attic after the work was done! It's this kind of attention to detail that makes them stand out. The pictures speak for themselves. If you want true professionals who care about safety, honesty, and quality craftsmanship, go with United HVAC.Posted on Google Chaozhong LianTrustindex verifies that the original source of the review is Google. I highly recommend United HVAC, Plumbing & Electrical! From start to finish, the entire process was incredibly smooth. They handled all the permits and inspections throughout the project, which gave us complete peace of mind. Every single technician we interacted with was friendly, approachable, and truly easy to work with. I specifically want to give a massive shoutout to Max (Aiusha) and Rinat for their wonderful work. Max is super professional and highly skilled. He installed my water heater and water softener with absolute "military precision." I'm the kind of guy who has a lot of weird, specific ideas about how pipes should be routed and extra gadgets I want installed to monitor the system, and Max handled all my requests with total ease. I am also super paranoid about plumbers plowing through studs or structural beams in my 1961 house, but Max was extremely careful and treated my home's structure with the utmost respect. Rinat is also a fantastic plumber. He installed a PRV, a Moen Flo auto-shutoff valve, an RO system, and even replaced some of the old sewage pipes in my house. He really listened to all of my requests and finished the job quickly and professionally. I highly recommend him! Because of their wonderful service, I’ve officially signed up for their company's membership. I am currently working with them to redo my HVAC ductwork, and I will definitely leave another review for that project once it's done. I'm sure they will do a wonderful job there, too!Posted on Google Ritesh BediaTrustindex verifies that the original source of the review is Google. Great service. Loved the professionalism and the way fixed my plumbing problem. I would call them again.Posted on Google Ginger PerngTrustindex verifies that the original source of the review is Google. We had to replace the wax ring on our toilet. Scheduling was easy; pricing was fair (much cheaper than the other quote we got!) Our technician, Melvin, was polite and expedient. This is our second time using United and highly recommend for gas and plumbing services.Posted on Google Joseph MartinTrustindex verifies that the original source of the review is Google. Melvin was great. Fast and efficient.
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