• Bosch
  • Navien
  • Noritz
  • Takagi
  • Rinnai
  • Bosch
  • Navien
  • Noritz
  • Takagi
  • Rinnai

Why Just Tankless?

Just Tankless is a company specializing in selling, servicing, repairing, and installing tankless water heaters for almost 20 years. We are the only company in the San Francisco Bay Area focusing solely on tankless water heaters, unlike other plumbing companies offering a more comprehensive range of services.

Our team is trained, certified, and recommended by all major tankless water heater manufacturers, including Bosch, Navien, Noritz, Rinnai, Takagi, and Bradford & White. We pride ourselves on our expertise and long experience in this field.

At Just Tankless, in addition to a Plumbing license, we also hold both General Building and Electrical licenses, allowing us to provide a one-stop service for all tankless water heater installations requiring plumbing, electrical, and general building licenses. This saves our customers money by not having to hire other contractors. In addition, we are in excellent standing with the California State Licensing Board, and you can check our licenses on their website.

How does a Tankless Water Heater Work?

A Tankless Water Heater saves energy by not having a storage tank full of heated water 24/7. Water is heated only on demand and at a much higher efficiency.

how a tankless water heater works

What is a Tankless Water Heater?

As the name suggests, a tankless water heater does not have a storage tank like a traditional water heater. Instead, it heats water on demand as it flows through the unit. This means that it only heats the water you need when needed, resulting in significant energy savings compared to a traditional tank model.

Advantages of a Tankless Water Heater

There are several advantages to choosing a tankless water heater over a traditional tank model:

  • Energy Efficiency: Tankless water heaters are highly efficient because they only heat the water you need. This means that they use less energy overall, resulting in lower utility bills.
  • Space Savings: Tankless water heaters are much smaller than traditional tank models, so they take up less space in your home.
  • Longer Lifespan: Tankless water heaters typically last longer than traditional tank models, with a lifespan of up to 20 years or more.
  • Consistent Hot Water: With a tankless water heater, you'll never run out of hot water. The unit heats water on demand, so you'll always have a steady supply of hot water whenever you need it.
  • Cleaner Water: Tankless water heaters don't store water in a tank, which means there's less chance of bacteria or other contaminants building up in the unit.

If you're interested in installing a tankless water heater, it's important to have a professional handle the installation process. At Just Tankless, our team of experts can help you choose the right unit for your home and ensure it's installed correctly.

Frequently Asked Questions

  • Is a tankless water heater something new?

    No, Tankless Water Heaters have been around for decades in other parts of the world, mainly in Europe and Asia.

  • What is a condensing tankless water heater?

    A condensing tankless water heater is a type of tankless water heater that is designed to be more energy-efficient, typically around 95% efficient, compared to non-condensing models that are approximately 80% efficient. These water heaters utilize a secondary heat exchanger to extract heat from the exhaust gases produced during the combustion process. This captured heat is then used to preheat the water as it flows through the primary heat exchanger, resulting in increased energy efficiency and cost savings.

  • Which is the best tankless water heater brand?

    The best brand and model of tankless water heater for your needs will depend on the capacity, type (condensing vs. non-condensing), installation location, and desired features (recirculation, WiFi, etc.). At Just Tankless, we are not tied to one manufacturer like other plumbing companies and represent all major brands. This allows us to recommend the best brand and model for your specific needs, and we want to ensure that our customers have many years of trouble-free operation.

    Each brand has its unique advantages. For example, we recommend the Takagi brand for outdoor installations with few features. On the other hand, for high-capacity, high-efficiency units with hot water recirculation and optional WiFi, we like Navien and Rinnai brands. Their top-of-the-line units feature stainless steel heat exchangers instead of copper, which is more durable and requires less service in areas with hard water containing many minerals.

    We also recommend the Noritz and Bosch tankless water heaters, which have excellent models. We recommend Navien, Rinnai, Noritz, Takagi, and Bosch brands. Each manufacturer has models which are best for certain applications. We like the Takagi for lower capacity non-condensing units for outdoor installation. For high capacity, high-efficiency applications, we recommend the Navien and Rinnai condensing units with their dual stainless steel heat exchangers for durability and efficiency.All manufacturers offer lower-priced models, which could serve well depending on the application. All manufacturers offer lower-priced models, which could serve well depending on the application.

    At Just Tankless, we offer our expertise and long experience free of charge to help you make the best decision for your needs.Please contact us for our recommendation for your application. We carry all major brands and have deep expertise in them and are not tied to a single brand like other companies.

  • What brands does Just Tankless offer?

    Our company stands out from others in that we offer all major brands of tankless water heaters, including Bosch, Navien, Noritz, Takagi, Bradford & White, Rinnai, and more. We also keep a large inventory of tankless water heaters for various applications.

    Moreover, we carry numerous replacement parts and can provide same-day service, unlike other companies that require ordering the parts, leaving the customer without hot water for several days.

    Although Quietside and Eternal Hybrid water heaters are no longer available in the US, we can still service them and have some parts available.

  • Which models of tankless water heaters do you carry?

    We stock all the latest models from Navien, including the NPE-240A2, NPE-210A2, NPE-180A2, and the NPN series. For Bosch, we carry the Greentherm 9000 Series and the non-condensing Therm Series. Our selection of Rinnai includes the Sensi Series, RSC199iN, RUR199iN, RU199iN, and non-condensing RE Series, all available in Natural Gas or Liquid Propane configurations. We also stock Takagi's T-K110, T-K310, and T-K510 non-condensing units and their T-H3 condensing units. Finally, for Noritz, we carry the NRCB199, NRCR111, NR98, NRC98, and many other models.

    We offer indoor and outdoor models in Natural Gas or Liquid Propane configurations. Contact us to help you choose your application's best brand and model.

    Additionally, we carry hybrid water heaters such as the Rinnai Demand Duo Series (CHS 13080H) and Noritz Hot Series (NHH199100-1-NG), which are ideal for commercial properties such as restaurants and hair salons, as well as apartment buildings.

  • Which communities do you serve?

    We provide Servie, Repair, Replacement and Installation in the greater San Francisco Bay Area cities of Alameda, Alamo, Albany, Antioch, Atherton,Bay Point, Belmont, Belvedere, Benicia, Berkeley, Brentwood, Brisbane, Burlingame, Byron, Campbell, Castro Valley, Clayton, Colma, Concord, Contra Costa County, Corte Madera, Cupertino, Daly City, Danville, Dublin, East Palo Alto, El Cerrito, El Granada, Emeryville, Fairfax, Fairfield, Foster City, Fremont, Greenbrae, Halfmoon Bay, Hayward, Hercules, Hillsborough, Kensington, Kentfield, Lafayette, Larkspur, Livermore, Los Altos, Los Altos Hills, Los Gatos, Marin County, Martinez, Menlo Park, Mill Valley, Millbrae, Miliptas, Monte Sereno, Moraga, Morgan Hill, Mountain View, Newark, Novato, Oakland, Oakley, Orinda, Pacifica, Palo Alto, Piedmont, Pinole, Pittsburg, Pleasant Hill, Pleasanton, Portola Valley, Redwood City, Richmond, Rodeo, San Anselmo, San Bruno, San Carlos, San Francisco, San Jose, San Leandro, San Lorenzo, San Mateo, San Pablo, San Rafael, San Ramon, Santa Clara, Saratoga, Sausalito, South San Francisco, Stanford, Sunnyvale, Tiberon, Union City, Vallejo, Walnut Creek, and Woodside.

  • Are there any tax credits or rebates for tankless water heaters?

    Yes, click here for more information.

  • Will there be any difference in usage?

    No, in some cases, you may get hot water sooner to your shower head or faucet than before because of the new location of the water heater being closer to the point of use. A smart-reticulating system design can give instant hot water at any faucet or shower head. We’ll be glad to share more information with you.

  • Where is the tankless water heater installed?

    The location of installation is significant for trouble-free operation. All crucial factors are adequate venting, oxygen, plumbing, and sufficient gas supply. Our experienced personnel will gladly discuss all available options with you.

  • Are there any special requirements for tankless water heater installation?

    Yes, since water is heated instantly, more heating energy is needed, which requires a slightly larger gas line to provide the additional gas volume needed. This is updated as part of the installation.

    Tankless water heaters don’t have an always-burning pilot-like tank type; they are pilotless but need electricity to ignite the gas initially. The electricity usage is very minimal. A new electrical connection will be provided as part of the installation.

    As water is heated instantly, more heat is produced that sometimes requires special venting; this installation depends

  • Can I install a tankless water heater myself?

    Expert installation is critical to safety, trouble-free operation, and manufacturer’s warranty. As with any potentially dangerous situation, it is best to use a licensed and factory-trained plumber, gas fitter, and electrician. Besides voiding the manufacturer’s warranty use of unqualified persons can be dangerous when handling gas, water, and electricity.

  • Is there any permit needed to install a tankless water heater?

    Yes, there is a permit needed from the local building department. We will gladly start the permit application process, ONLY charging you the Permit Fee with NO markup! We will send the completed Permit to your Home; you can call the Permit department for inspection after finishing work.

  • Fluctuating water temperature at the shower?

    When experiencing fluctuating water temperature in your shower, it is often not the fault of the tankless heater but rather the shower fixture. Many of the German brands Grohe and Hansgrohe fixtures cause the problem. They have a built-in thermostatic valve that tries to control the water temperature at the institution and limit the max temperature. It then oscillates between lukewarm and hot as its thermostatic valve opens and closes. There is an internal adjustment to raise the temperature setting, but these fixtures are over-engineered and trouble some besides being expensive.

    They may work well in Germany as many towns have central water heating. Yes, central water heating! You get hot water delivered just like cold water; the hot water is often boiling. There are two water meters, one for hot and one for cold. The hot water is generated by garbage incinerators, cooling water from nuclear power plants, etc., and pumped throughout the town. Each home or building has a heat exchanger to extract the heat.

  • Why not buy a tankless water heater from Amazon, Ebay, Home Depot or other warehouses?

    We recommend local plumbing companies who are experienced and are at hand when you need service. Having to wait on service for hot water can be very frustrating. Using local plumbers also helps your community by supporting local businesses.

    Amazon and others have started selling services online for referral; they demand about 20% of the total cost. That is steep and something the local plumber has to make up for it in other ways with the customer, and not always in a transparent manner.

    If something goes wrong, the customer is caught between the seller (i.e., Amazon) and the installer (plumber), each pointing to the other for being responsible.

    Similarly, this is the case buying from Home Depot, Lowe's, or other large stores. They subcontract the installation through a referral with steep referral fees from the installation company.

    Some retailers even use out-of-state companies to install, and when the time comes for service, they need to be more responsive.

    Our price checks have shown no price advantage compared to the local company selling and installing the tankless unit. Oversized boxes and online referred installation companies tend to be more expensive because the installation company has to make up for the hefty referral fees.

    Additionally, Tankless Water Heater Manufactures require an installation by a certified installation company for the tankless water heater to be warranted.

  • What is Water Recirculation, and how does it work?

    In all water heating situations, storage tank or tankless, the hot water has to travel from the source where it is being heated to the point it is needed through pipes, mostly copper pipes. The time it takes to get hot water where it is needed depends largely on the distance of pipes from the source to the destination. The hot water pipes hold hot water which cools over time and need to be drained first before the heated water can reach the destination, for example, the shower. Depending on the distance and pipe volume and length, that can take a long time, waiting for the hot water to arrive and wasting a lot of water in the meantime. There can be a significant amount of water in larger, multiple-story homes that is drained and wasted.

    There are two types of recirculations, dedicated and non-dedicated.

    Dedicated Recirculation

    Some homes are built with a dedicated recirculation line. That is a third water line in addition to the cold and hot water lines, installed at the time of construction. This third line brings the hot water line from the farthest point of hot water point of use back to the water heater. The water heater is then able to circulate the water in the hot water line with the help of a pump and keep the water always hot in the hot water pipes, hence providing near instantaneous hot water at the destination and eliminating the wait for hot water, and no water is wasted down the drain.recirculation illustration

    Non-Dedicated Recirculation

    The majority of homes, small or large, do not have dedicated recirculation, although in our opinion, this should be part of the building code, allowing for significant water saving.

    In many cases, it is not feasible to install a third water pipe for a dedicated recirculation in existing homes. In these cases, a special valve called a recir valve, crossover valve, or comfort valve is installed at the farthest hot water destination. This valve is thermostatically automatically controlled and opens and closes depending on the water temperature on the hot water line, usually 120F. This valve provides a conditional bridge between the hot and cold water pipes.recirculation valve

    At the heater, storage tank, or tankless, there is a pump that pushes hot water in the hot water line, and as long as the water is not 120F at the valve, it provides a bridge and allows that water to flow into the cold water line and be reused by the heater, so no water is wasted. This special valve allows creating a loop in the hot water line and hence water to be recirculated. There can be multiple of these valves, and multiple loops be created with a single pump at the heater.recirculation pump

    Please watch this short video for more detail.

  • How is Recirculation controlled?

    Even though the energy usage for recirculation is minimal, there are multiple methods to control recirculation. In tank storage cases, the recirculation pump can be controlled with a timer to enable recirculation only during certain times, for example, during waking hours.

    The latest generation of tankless water heaters, like Rinnai model RSC199iN, RSC199eN, Navien NPE240A2, NPE210A2, Noritz NRCR92, and Takagi TK-540P-NIH offer integrated recirculation pumps with connectivity through WiFi and On-Demand, timer scheduled, or self-learning recirculation. With Machine Learning software, the tankless water heater can adapt the recirculation to usage habits automatically.

    We at Just Tankless are specialized and can gladly advise you on all available options and help select the best option for your needs. Please contact us at 408-357-3280.

    Please watch this short video for more detail.

  • Do tankless water heaters need maintenance?

    It depends on the water quality. Just like storage tank water heaters, hard water, that is water with a high content of minerals, leads to scale buildup inside the heater. This scale builds up inside the heat exchanger of the tankless water heater and needs to be removed. Commonly referred to as flushing (Descaling) the tankless, it entails removing the mineral buildup by circulating food vinegar or CLR through the heat exchanger.

    In geographical areas where the water is soft, there is no need to flush the tankless. This is mostly the case where city water comes from water reservoirs rather than water wells. The scale buildup is also an issue with storage tank water heaters, where it collects at the bottom of the tank and leads to premature tank failure, water leakage.

  • Are Water Softeners a good idea?

    In general, yes, depending on the type. Salt, Potassium-based softeners work great but introduce Salt into the plumbing system. Salt is corrosive and damages pipes, appliances over time. Additionally, these softeners waste 15-20 gallons of water during the regeneration cycle, which could be a few times a week. Many municipalities don't allow their installation because of the salty drain water damages city plumbing.

    By definition, anytime minerals are removed from water, it is softened. Large capacity filtration is an effective, economical, and environmentally way to remove minerals. Many times minerals occur in solid forms and can easily be filtered. Multiple-stage high-capacity filtration helps softening the water. In a 3-stage system, the first stage traps particles greater than 5 microns in size, the second stage is a carbon filter, and the third stage is a charcoal filter. The filters are effective for 12 to 18 months and can easily be changed.

    Electrical or magnetic type of treatment are not proven to be effective at all.

    Please contact us for a recommendation at 408-357-3280 or at info@justtankless.com.

  • Why is my hot water only lukewarm or turns cold?

    There could be many causes for this, including the tankless water heater needing service. However, most of the time, the problem lies with defective fixtures. Many modern fixtures have built-in thermostatic valves where water temperature is regulated at the fixture. Such a defective fixture oscillates between hot and cold water in varying frequency by mixing cold water into the hot water, trying to regulate the water temperature. This, in turn, can cause the tankless water heater to shut down as it stops seeing hot water demand from the fixture. The Grohe and Hansgrohe brands of fixtures often cause this problem when they become older.

    Another common failure is cold water flowing into the hot water line at the fixture. This occurs in single-handle fixtures, like most shower fixtures, where the hot and cold water come into the fixture and are separated by a rubber membrane in the cartridge. The rubber membrane develops a tear over time, and such failure affects the entire plumbing system as there is only one hot water line throughout the house, making it difficult to determine which fixture is the cause. All single-handle fixtures in the hot water system may display the same symptom.

    Please contact us for service at 408-357-3280 or at info@justtankless.com for diagnosis and repair.

  • What do the error codes on my tankless mean?

    Tankless water heaters are computer-controlled and are able to self-diagnose and monitor problems within their operations. These closed-loop systems monitor water temperature, the heating process, and safety provisions. It varies its heating flame depending on the amount of hot water being demanded in gallons per minute and adjusts its gas valve and burner to deliver the hot water within 1 degree F of the desired temperature with a computer-controlled complex process. It has many sensors monitoring its operation, some even monitoring its burner flame efficiency with a camera for ideal gas combustion, a blue flame, for example, indicating the correct mix of gas and oxygen mixture.

    It will issue warnings and display error codes to help trained technicians diagnose the problem. Modern tankless water heaters don't have a continuously burning gas pilot flame. Combustion is initiated only when hot water demand is detected within fractions of a second. For example, a code 11 means ignition failure by many brands. That is, the unit could not initiate combustion. This could be because of a lack of gas supply, a faulty gas valve, defective ignitor, defective flame sensor, water in the burner chamber, or lack of combustion air. A trained technician can then diagnose the cause and take corrective action. Tankless water heaters have a sealed combustion chamber, also no open flames like the traditional storage tank water heaters.

    Tankless water heaters are high-powered gas appliances, often with 199,000 Btu/h capacity, and they are not DIY repair devices. We recommend contacting us for service at 408-357-3280 or info@justtankless.com.

  • Why use a factory-trained and certified company to install a tankless water heater?

    Tankless water heaters are sophisticated and expensive, and if properly installed, they will provide decades of trouble-free service. An untrained person may install a tankless and get it to deliver hot water; however, problems may develop later because of improper installation. As an example, we have often seen the tankless unit developing problems after a few years, displaying an error of 'incomplete combustion.' The tankless monitors its combustion as required by law for cleanliness and finds its exhaust temperature is too high and stops heating. This often happens because of near improper combustion for years, leading to soot buildup in the burner chamber due to improper gas pressure adjustment or no adjustment at the time of installation. Such premature failures are not covered under warranty by the manufacturer and result in costly repairs or the need for replacement.

    A trained technician has the training and all the needed test equipment for proper installation. The technician checks the gas pressure at the time of installation with a gas manometer, ensuring proper gas pressure and adjusting for correct operation for years. Manufacturers require expert installation for honoring the warranty and require trained technician installation.

    We carry all major brands like Navien, Rinnai, Noritz, Takagi, Bosch, and can recommend the best brand for your needs. We are a stocking dealer, which means we stock tankless water heaters and warranty them through us, unlike big box stores like Home Depot, Lowes, etc., who only pass through your order. They are also not set up to provide you with any kind of after-sale support or warranty. They will refer you to the manufacturer who, in turn, will only support certified technicians and companies. This leads to a headache for everyone except the big box store who sold the tankless.

    For superior installation and service, we require tankless units to be provided by us, and we are your single point of contact for warranty and service.

    Please contact us for price quotes at 408-357-3280 or at info@justtankless.com.

  • Do you carry heat pump water heaters?

    Heat pump water heaters are a relatively new technology in our area and are an excellent choice for high efficiency. As more and more cities move towards electrification strategies, many are looking to move away from natural gas. At our company, we offer all major heat pump water heaters brands, including Rheem, AO Smith, and Sanco. Our technicians are trained and certified to provide installation and maintenance services for these systems.

  • Do you carry Hydronic heaters for space heating and floor heating?

    We have expertise in hydronic heating and provide solutions for combined domestic water heating and space heating. Our specialization includes Eichler Homes and similar properties with in-floor, baseboard or radiator heating. Our Combi Boiler solutions are 95% efficient and can significantly reduce heating costs.

    In addition, we offer high-capacity, high-efficiency boilers suitable for commercial and apartment applications.

    The latest tankless boilers are designed to be long-lasting with high efficiency, such as the Noritz NRCB180 and NRCB199, Navien NCB 190/60 and NCB190/80, and Rinnai M Series M160CN.

Our Customer Love Us

  • ratings starratings starratings starratings starratings star

    Al helped fix my Noritz Tankless this morning. The heater had been giving me issues over a few days and water was intermittently not getting hot. I called another company and they checked the error codes but couldn't fix the problem..and then yesterday, it just stopped turning on.

    Al was responsive and frank on the phone that he couldn't help me with an intermittent issue given there is no consistent repro. After I called him a second time when hester stopped working, he stopped by and diagnosed the flow sensor to be the issue in no time. He cleaned and everything was working again.

    He also commented on my pump and polyphosphate filter setup and gave tips on how I could flush the heater myself. You can tell he has a in-depth technical knowledge of this.

    I would highly recommend his services. Thanks.

    Srinivasan R.



  • ratings starratings starratings starratings starratings star

    Al fixed my tankless problem within 10 minutes. My 9 year old tankless quit working this morning, no hot water. I contacted the installer but they couldn't come out until Monday. I discovered Just Tankless on Yelp and spoke with Al. He asked a few questions, and although he was busy he said he'd be here in 30 minutes. Amazing! Problem solved! Just Tankless will be my first call from now on!

    Rj J.


    San Jose, CA

  • ratings starratings starratings starratings starratings star

    Al does excellent work. He has installed two Rinnai tankless water heaters for me. No problems after five years on the first and 3 years on the second. He is also a great contracting resource. Upgraded old tile flooring with tile.

    Stephen P.


    San Francisco, CA

Read our reviewsyelp button