Bosch Tankless Water Heater Reviews | Brand Overview


Bosch was founded in Germany in 1886 and has a presence in over 150 countries, making it a near-global brand. Bosch’s mission statement suggests that they are a customer-oriented company focused on providing innovative solutions that improve quality of life. However, it is important to note that Bosch, unlike many other tankless water heater brands, does not exclusively focus on tankless water heaters. Rather, Bosch is involved in several technology-oriented industries, like automotive, consumer goods, and more.  

Bosch generally offers tankless, point-of-use and heat pump, gas and electric water heaters utilizing Bosch Thermotechnology. 

Bosch Tankless Water Heater Product Line Reviews

Bosch Gas Tankless Water Heaters

Greentherm 9000 Series

The Greentherm 9000 series is the newest line of condensing and tankless water heaters. Considered one of the most powerful residential tankless water heater that Bosch has to offer, it offers impressive performance and water flow despite its compact size. This highly efficient tankless water heater also offers a water flow of 11.2 gallons per minute (GPM) and a built-in recirculation pump, providing you with hot water instantaneously. 

The Greentherm 9000 series also merges eco-friendliness with state-of-the-art technology. These models have a built-in touch screen to adjust the temperature or check the diagnostics for easier repair, and integrated wi-fi allows the user to remotely control the settings from their mobile phone. These units cost around $1,000-$1,500 depending on the technical specifications of the water heater. 

Therm Series

The Therm series includes both condensing and non-condensing models and offers many of the same benefits as the Greentherm series. With a range of models in this product line, consumers are bound to find something that fits their budget. The models in this series have high water flow rates (ranging from 8.3-12.1 GPM) and are highly efficient, providing consumers with significant savings on their water bill. 

Designed as a wall-mounted water heater, the models in the Therm series save space without sacrificing design aesthetic. The LCD display relies on an internal PC board for real-time diagnostics and programming, and clearly shows error codes that make it easy for the consumer to troubleshoot and determine what repairs, if necessary, need to be made. These units also cost around $1,000-$1,500 depending on the technical specifications of the particular water heater. 

ProTL Series

The tankless water heaters in the ProTL series are essentially a replacement for the Bosch Greentherm C 950 series. Available both in condensing and non-condensing units, these models are highly efficient and provide reliable temperature stability. Additionally, these water heaters reduce emissions, making them particularly appealing to the eco-conscious consumer. What makes this series even more appealing is that these water heaters are designed to meet the demands of busy or large households and still prioritize efficiency.  

This is a special edition line of gas tankless water heaters and will only be available for a limited period of time. These units cost approximately $1,200-$1,500 depending on the technical specifications of the unit. However, these units are meant to be sold directly to contractors and plumbers “ so it may be difficult for you to find them at a local or online retailer. 

Electric Tankless Water Heaters

Tronic 6000C

The Bosch water heaters in this series are considered the most advanced tankless water heaters the brand has to offer and are the best electric models to buy when it comes to the number of features at the price point. Bosch advertises these water heaters as the ideal solution for homes where electricity is the preferred energy source. The models in this series are highly thermally efficient while still being compact and lightweight – they come in at a mere 20 and 22lbs respectively. 

The water heaters in the Tronic 6000C series are easy to install and ideal for large homes. With a 95% efficiency, you don’t have to worry about paying enormous water bills for hot water that you aren’t using. 

Bosch Tankless Water Heaters vs. Other Brands

Bosch vs. Noritz

Noritz produces and manufactures their tankless water heaters in Japan, and offer models suitable for both residential and commercial use. 

Noritz tankless water heaters have a wide range of price points as low as $1100 per unit, and up to $4000 per unit. However, most Noritz water heaters are priced under $2000. In contrast, Bosch offers much more affordable options (in the $575-725 range), but these are better suited to a 1-2 person household. 

Noritz offers the industry’s best warranty as long as a 25-year heat exchanger warranty for some models. Overall, they offer a 12-year, non-prorated warranty on every unit at a minimum. Bosch offers a 15-year warranty on the heat exchanger and a five-year limited warranty for replacement parts. Between the two brands, Noritz offers on average a slightly better warranty.    

Between Bosch and Noritz, Bosch is the more affordable brand but it seems that many customers are finding that the inexpensive option comes at a much steeper price. Noritz is the brand that comes out on top here. 

Bosch vs. Takagi

Takagi is a well-established business with over 60 years of experience prioritizing safety, quality, and service in every product. Their price point per unit ranges from $750-1250, making them only slightly more expensive than most Bosch products. 

In product reviews, customers who purchased a Takagi water heater reported high satisfaction with their product, its durability and efficiency, and the water flow rate (10 GPM!). The Energy Start-compliant models provide for venting flexibility and have an electric freezing protection system. 

Takagi offers a 15-year limited warranty on products, a residential five-year limited warranty on replacement parts, and a one-year warranty on labor. Like Noritz, Bosch’s warranty is competitive but still falls just short. 

Bosch vs. Rheem

At first glance, Rheem and Bosch offer similar tankless water heaters for a similar price point, making them direct competitors. This is true, as both brands offer quality products with similar technical specifications and features. However, Rheem tankless water heaters provide hot water much more quickly than Bosch and customers are consistently more satisfied with their Rheem water heaters than their Bosch counterparts. Rheem also offers a high water flow rate (9.8 GPM max across numerous machines) and a built-in recirculation pump that provides hot water almost instantly. 

This isn’t to suggest that Bosch does not have tankless water heaters that are significantly better than what Rheem has to offer. Rather, when comparing similar models, Rheem appears to offer better features and performs better at the same or similar price. 

Bosch vs. Rinnai

Rinnai has one of the best reputations in the industry as a top-quality brand. Rinnai is reliable and works very well, however, these water heaters are typically sold at a higher price point than Bosch. Although Bosch offers a larger product line with a huge range of parts and equipment, Bosch tankless water heaters consistently receive average to good ratings from consumers. Rinnai tankless water heaters, in contrast, consistently get high marks in terms of customer satisfaction. 

Rinnai also has more state-of-the-art technology integrated in their tankless water heaters. If integrated Wi-Fi and Alexa compatibility are important to you, then Rinnai will be the better fit for your lifestyle. 

Between Rinnai and Bosch, the former generally wins in terms of technical specifications. However, they are both competitive brands and whether a brand is better over another will boil down to individual consumer’s needs. 

Bosch vs. Navien

Navien is a fairly new brand to the U.S.A., so it cannot offer the same brand leverage that industry titans like Bosch have. Accordingly, Navien hasn’t had the same opportunity to build brand presence and invest in marketing. 

Navien tankless water heaters are sold at a significantly higher price point than Bosch, but these energy-efficient water heaters perform extremely well and are very reliable. This ultimately results in long-term financial savings and appeals to the more eco-conscious or economical consumers.  The biggest drawback is that Navien tankless water heaters are not easily accessible through major retailers such as Home Depot, Lowe’s, or Amazon. Accordingly, it is difficult to determine what customer perception is in comparing Bosch to Navien. 

Bosch Tankless Water Heater Cost

Bosch offers a wide range of price points to suit consumers on any budget. 

For example, for the Tronic 3000, many units cost under $250. Some of the more high-powered tankless water heaters, like seen here, can be a little more expensive. At the time of writing this article, th e price range was $600-700 per unit. Tankless water heaters in the Therm series run an average of $1000-1500. The next step up, the Greentherm 9000 series, ranges from $1200-$2500. 

Installation costs for Bosch tankless water heaters range from under $600 to approximately $1,500, depending on the scope of the project. 

Bosch Tankless Water Heater Maintenance

Bosch tankless water heaters should have regular maintenance, just like all other tankless water heaters. At least once or twice a year, a tankless system should be flushed to prevent buildup and all parts should be inspected to determine if there is a need to repair or replace anything. 

Bosch unlike many of its competitors makes obtaining information about products and their maintenance easy and stress-free. On their Documents & Media webpage, consumers can explore downloads for current and discontinued Bosch products. This includes brochures, manuals, service bulletins, and more. So, even if you have misplaced the original user guide for your Bosch tankless water heater, the company still sets you up for success.   

Bosch Tankless Water Heater Parts

Bosch offers a link that makes searching for replacement service parts hassle-free. Bosch tankless water heater replacement parts are easy to come by even if you don’t (or can’t) utilize the link. Plumbing Supply, for example, lists several Bosch tankless gas water heaters here alongside required or optional accessories and their respective prices. Supply House also lists a number of replacement parts here, from water filters to water heater gaskets, regulating knobs to gas valves. 

Bosch Tankless Water Heater Service

Bosch’s website allows users to search for an installer or contractor near your location here. A brief search using a zip code returns both a map with identified locations, as well as a list of nearby businesses, their respective addresses, and the services they provide. Searches can be further refined based on product categories, service needs, and proximity. 

Bosch Tankless Water Heater Warranty

Bosch offers consumers a complete library of product warranties for current and discontinued products, making it a breeze to check the warranty on an older-model water heater even if you did misplace the user guide. The Water Heater Warranty Documents page breaks down in an intuitive and easy-to-read format current and archived products and their respective effective date.  Consumers will appreciate how easy it is to find information for their specific model of Bosch water heater from the simple layout and associated download links. 

Bosch Tankless Water Heater Customer Service

Bosch promises to provide comfort and peace of mind to our customers. Their Customer Service page is very thorough, offering hours, multiple telephone lines, fax numbers, and physical addresses. 

Residential Telephone: 800-283-3787
Commercial Telephone: 800-326-1400
Fax: 603-965-7568
E-mail for Tankless Tech Support:
E-mail for Residential Products:
Warranty & Returns: 

Additionally, the Bosch website offers a general inquiries page if your question, comment, or concern does not neatly fall into one of their many categories. You can find that page here

Bosch Customer Reviews/Perception

Customers seem to be split when it comes to Bosch tankless water heater products. For example, for this particular model, several customers express that their new tankless water heaters failed quickly or needed repairs, or that they were unable to utilize their product’s warranty (although the warranty had not yet expired). Other customers complained of poor customer service, particularly that they were unable to provide reasonable solutions to common issues. Other customers found that their tankless water heater worked well and did not experience any issues, even when they needed to contact customer service. 

The same mixed feelings can be found in reviews for this model of Bosch tankless water. Many customers complain of poor quality models that break very quickly, while others seem thrilled with their new water heater. Bosch’s customer service also splits fairly evenly with many customers either loving it or finding it completely useless.  

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