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Bosch Instant Hot Water

It goes without saying that Bosch is one of the top brands in the market when it comes to domestic and commercial water heaters. Through the years Bosch has developed a reputation for superior quality and reliability of their products. Besides, the company has a long association with Australia and plenty of Australian homes have found it a trusted brand.

Three points that separate Bosch instant hot water technology from the competition are:

  1. High-quality and advanced heating technology
  2. All products ensure high efficiency and environmental safety
  3. Lifetime service for the appliance

So, what is the best Bosch instant water heater?

In this article, we look closely at the top Bosch products to help you find out the answer.


If you are looking for high-end engineering and lower utility bills, Bosch water heaters are some of the best options you can pick. 

Bosch water heating systems offer the advantage of operating without the need for electricity. This gives additional flexibility for installation in various settings. Most importantly, the high efficiency of the heat exchangers delivers hot water at a moment’s notice while maintaining good flow rates.

These instant hot water systems are also robust enough to withstand the variations of the Australian climate. As a result, these products from Bosch can deliver trouble-free service for years with minimum maintenance. The compact size of the systems also makes the process of installation simple, especially in small spaces.

While Bosch heaters are not the cheapest option in the market, the high efficiency and durability of the products make them a good choice. Bosch doesn’t have a wide range of water heaters like some other players in Australia’s residential hot water industry. Still, that might be a good thing, as it makes it easy for you to differentiate between the offerings.

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Company Background

Founded in 1886 by Robert Bosch, Bosch is a German multinational technology and services company. With its headquarters in Gerlingen, Germany, the company has multiple business sectors. As mentioned on their website, the fundamental principle of the brand is “innovative strength and social commitment”. 

Here is a closer look at their story:

  • Bosch has been in Australia since 1907 and it has its headquarters in Clayton, Victoria. Currently, it generates revenue that is around 1.18 billion Australian dollars per annum. 
  • The different sectors of Bosch Australia include mobility solutions, industrial technology, consumer goods, and energy and building technology. 
  • Bosch Thermotechnology offers innovative energy-saving heating and air conditioning solutions across the globe. At present, it employs more than  390,000 men and women.
  • Apart from hot water and heating solutions for the home, Bosch also offers various home appliances and power tools.

Bosch Tankless Hot Water System Range

Bosch HydroPower Heaters

What to love about the Bosch HydroPower water heater:

  • Uses an efficient hydropower ignition technology
  • Continuous flow technology for energy saving
  • A sturdy design
  • Three different models with varying capacities

The best feature of the Bosch Hydropower water heater is it uses innovative technology for automatic ignition. That means you can operate the device without a power point. The power source for the Hydropower units is gas. The maximum gas consumption varies between 79 MJ/h to 130 MJ/h depending on the model size.

A turbine operated by the force of flowing water forms the core of the Hydropower system. The tiny turbine helps in generating a spark that ignites the gas and initiates the heating process. This makes the unit an ideal choice for tackling electricity outages. Since it will not use any energy when not in use, it is also a power-saving device.

Another great feature of Bosch Hydropower is the convenience that it offers. The heater will automatically switch on when you turn on your hot water tap. Once you turn the tap off, the system will automatically shut down. 

Moreover, the entire Hydropower range comes with a 5-star rating. So, you can count on it being energy-efficient and help you save gas bills. The water temperature can be controlled by adjusting the water flow rate or the burner power.

The Hydropower systems are designed for external mounting and come in 10L, 13L, and 16L capacities. The figures also indicate the flow rate of the units. Bosch offers a 2-year warranty on parts and labour and a 10-year warranty on the heat exchanger. Besides, the unit is also easy to install.

The Bosh Hydropower system is expensive. But if you want a gas-powered water heater, it is one of the top options on the market.

Bosch Pilot Ignition Heaters

Here are the highlights of the Bosch Pilot Ignition water heater:

  • Supplies hot water on demand
  • Can be installed in any convenient location
  • Compact design and easy to install
  • An affordable price tag

The Pilot Ignition system is an affordable externally mounted hot water system from Bosch. The unit can function in an area without a power point and it uses continuous flow technology. That means hot water is delivered only when you turn on the tap, thereby reducing energy wastage.

Functionally, the ignition mechanism in the system is through the pilot light technology. The pilot light ignites the gas when it is released into the burner. The downside is that you need to check if the pilot gas is lit through the small glass window. Some users may not find it easy to see through the glass. So the next best step is to check if the water is heating up. 

There are a series of buttons in the front panel of the device to relight the system. The whole process takes around half a minute. However, many users have mentioned that the light keeps going out frequently. As expected from Bosch, the build quality is top-notch and installation is easy.

The Pilot Ignition heating system comes in two sizes, 10L, and 16L. While the smaller unit functions with both natural gas and LPG, the larger unit works only with LPG. The gas consumption rates for the two models are  79 MJ/h to 130 MJ/h respectively.

In terms of energy efficiency, the Pilot ignition products are not on par with the Bosch Hydropower heaters. Both these models have star ratings of around 4.5 which is average at best. 

Overall the pilot ignition system is an affordable option for small households and apartments. While it’s not the most efficient system from Bosch, it still offers great value.

Bosch Internal Compact Heaters

Main features of the Bosch Internal Compact water heater:

  • Comes with Hydropower ignition technology 
  • Does not require electricity for operation
  • Compact and easy to install indoors
  • Aesthetically pleasing design

The Internal Compact system uses the innovative Hydropower ignition technology with an environment-friendly design. What makes it different is the compact shape that allows you to mount it on the inside of your home. However, you need to pick a spot with an adequate air supply and ventilation.

Bosch offers three variants of the model with flow rates of 10, 13, and 16 litres per minute. All three units can run on natural gas as well as LPG. In addition, the unit comes with a temperature controller and a digital display. 

Like the other heaters from Bosch, this range is equipped with continuous flow technology too. So the heater burns gas only when required.

Note, the 10-litre unit is the most economical choice with a star rating above five. The other two models come with ratings below five. The other thing is, the minimum water pressure required for all the models is 50 kPa.

Keep in mind, as per AS/NZS 5601, internal heaters need to be mounted with the necessary fluing arrangements. Bosch does not supply the fluing components with this heater. That makes the installation more complex. However, being an internal-mounted device, it is ideal for frost-prone areas. 

In short, if you are planning to replace your old internal heaters, the Bosch Internal Compact heaters are a smart upgrade.

Bosch OptiFlow Professional Heater

A quick look at the top features of the Bosch Optiflow Heater

  • Optimized combustion through the patented combustion management system
  • Delivers high flow rates starting from 16 litres per minute
  • Compatible with natural gas and LPG
  • Multiple safety features

The Bosch OptiFlow range is one of the most advanced external mounted water heaters from the brand. One of the best features of this range is the combustion management system controlled by a patented algorithm. The system automatically controls the gas flow rate and the fan speed to ensure optimum efficiency under a variety of operating conditions. 

Note, the Optiflow units require a power supply to operate. So you do not get the flexibility for installation like the other models. The devices use the Bosch “Easy Minimum” technology that allows them to run with minimum power consumption. All three units come with a 6-star rating that ensures optimized power consumption.

In terms of capacity, the Optiflow range is available in 16L, 20L, and 26L flow rates. As expected, the gas combustion rate of the models is higher. The maximum gas combustion of 20L and 26L units are 149 Mj/h and 199 Mj/h respectively. Bosch has equipped the devices with temperature sensors and safety devices like a flame sensor and a thermal fuse.

Besides the Optiflow series of products come with a warranty of 3 years on parts and labour. The warranty on the heat exchanger is 3 years. One big advantage is that all three units are solar compatible. They also come with frost protection technology for operating in extreme conditions.

The Optiflow Professional is a top-end product from Bosch that comes with multiple advanced features. However, this range is best suited for larger households that require a higher water flow rate.

Accounts In the Wild

We checked out some of the customer feedback received by Bosch products. Here are some snapshots from customers:

This indicates the high quality and durability of Bosch products. After using a unit for 14 years, the customer was ready to replace it with an upgraded model.

This review for the Bosch Hydropower unit indicates how important it is to pick the right flow rate and get the unit installed in the right manner. Make sure to take professional help to adjust the flow rate of Bosch tankless heaters during installation.

Although Bosch ensures high quality, some customers have faced issues related to hot water delivery. Clearly, the customer service team was able to fix the issue.

Performance Notes–How does it stack up where it matters?

When it comes to water heaters, there is no “one-size-fits-all” option. But the advantage of tankless heaters is they are not limited by their tank sizes. Anytime you need hot water, the water flows in, gets heated, and flows out. And with the top-grade quality offered by Bosch, you get a higher life span than traditional water heaters.

Choosing the Type of Tankless Water Heater

Gas vs Electric Heaters

The two main types of tankless water heaters are gas and electric. This is a critical choice as it will impact your annual operating expenses.

Gas-powered heaters deliver higher heat and heat up the water quickly. Since gas is cheaper, they are also more economical in the long run. However, they have higher installation costs and need more maintenance.

Electric heaters are preferred for indoor use as they need no ventilation. They are also cheaper and installation charges are on the lower end. Keep in mind that electric heaters require a significant amount of energy. So, in older homes, upgrading the electrical system may be required for installation.

The Bosch range of water heaters in Australia has gas-powered models only. If you prefer an electric heater, you need to check out the other top brands.

Indoor vs. Outdoor Heaters

The next aspect of choosing a heater type is picking between indoor and outdoor units. Bosch has both types of heaters in its product range. 

Like all outdoor heaters, Bosch external heaters have a robust design and do not need ventilation and a flue arrangement. Some of the models also come with frost-eliminating mechanisms. 

Generally, tankless heaters with a higher flow rate also have a larger size. So you also need to take a look at the space requirements. This is where the compact size of the Bosch indoor heaters can be a big advantage.

Flow Rate

Note, tankless heaters are all about on-demand hot water supply. So you need to pick the right flow rate in litres per minute to ensure a steady hot water supply during peak demand. The right flow rate will also eliminate lag time and deliver hot water quickly without you having to wait for it.

The easiest way to calculate this is to find out the individual flow rate for each appliance you will connect the heater with. Then, add up all the numbers to find the total flow rate. 

Ideally, the minimum flow rate of a water heater should be around 12 litres per minute. Most Bosch heaters start with a minimum rate of 10 litres and then move higher.

Overall, the flow rates of the Bosch instant hot water systems are competitive. The good thing is that Bosch offers multiple variants of each model to suit households with different hot water requirements.


The price of any tankless heaters will depend on the size and flow rate. A high-quality gas-powered tankless heater can be priced between  $800 to $1,200. Add to that the cost of installation.

In terms of value, Bosch water heaters are right at the top end of the chart. Considering the high engineering standards of Bosch, it’s not surprising that these heaters deliver good energy efficiency. This is also a result of the well-designed heat exchangers that deliver a high coefficient of performance. Even so, the overall performance figures are not the best in the market.

Compared to the competitors, Bosch instant hot water devices come with a relatively higher price tag. But, the payback period is on the shorter side. Add to that, the excellent durability that ensures long-lasting performance.

Warranty and Support

It goes without saying that Bosch uses time-tested technology in its products. Bosch offers a 2-year warranty on all its products and a 10-year warranty on the heat exchanger. It also mentions a service offering throughout the life of the product. However, there are other brands that offer longer warranties on their heaters.

Ideally, a tankless water heater should be serviced by a professional once a year. So the quality of service that a brand delivers is important. Bosch customer support is responsive, but for some customers, it has been a mixed experience. We think this is an area where Bosch needs to do better.

Frequently Asked Questions

What is the downside of a tankless water heater?

The two main downsides of tankless water heaters are the high initial cost and installation charges. Also, picking a device with the right flow rate can be complex. This can result in an inconsistent water temperature under a high load.

Can I install a tankless water heater myself?

Installing a tankless heater can involve setting up new electrical wiring or gas lines. Since handling gas and electricity is a high-risk task, we suggest that you enlist help from professionals to get the job done.

How long do tankless water heaters last?

A top-grade tankless water heater can last for 15-20 years with the right maintenance. Since most of the components are replaceable, their lives can be extended even further.

Bottom Line 

To sum up, Bosch instant hot water systems are one the best tankless designs that you can pick. Bosch doesn’t offer a wide range of products and not all their models are affordable options. Even so, their superior engineering and reliable build quality are hard to beat.