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Rinnai – instantaneous electric water heaters in 21, 24 & 27kW coming soon

The KW rating within the Rinnai instantaneous electric water heater range is scalable from 21kw, 24kw and 27kw ensuring suitability for a wide variety of applications. A compact design allows easy installation and is proven to increase energy efficiency and therefore reducing operational costs. Ease of installation and handling are a major feature.

Rinnai’s new range of instantaneous electric water heaters are suited to all commercial and domestic applications that require decarbonising technology capable of delivering domestic hot water needs.

Rinnai’s innovative approach to producing decarbonising technology has resulted in a DHW electric water heater that has been designed to offer direct heating capability. The technologically advanced bare wiring technology rests in the water enabling the system to achieve the pre-set water temperature quickly and accurately. The electric on demand water heaters are lightweight (less than 4kg) and diminutive (450 x 235 x 94). Rinnai is continuing to provide UK customers with an array of products that cover a range of energies.

For a brochure on the Rinnai range of electric on demand water heaters and low carbon technologies visit and receive a goody bag.

The KW rating within the Rinnai instantaneous electric water heater range is scalable from 21kw, 24kw and 27kw ensuring suitability for a wide variety of applications. A compact design allows easy installation and is proven to increase energy efficiency and therefore reducing operational costs.  Ease of installation and handling are a major feature.

Rinnai’s instantaneous on demand electric water heater range can maintain an adjustable temperature range from between 20 and 60 degrees Celsius and that can be digitally increased in 0.5 degrees increments. All units can also accept preheated water.

Other features that the Rinnai instantaneous electric water heaters include:

  • overheat protection
  • multi-functionable display
  • full electric control
  • rapid heat up capability
  • quick reaction to sudden shifts in grid capacity output.
  • solar compatible.

All models have LCD screens that provide visual information on current water temperature, operational performance and Eco Mode – which supplies confirmation of the appliance operating economically and therefore reducing unnecessary energy wastage and costs.

Rinnai’s instantaneous electric water heater has a renewable system operation setting that recognises incoming water temperatures more than 30 degrees Celsius, then applies only the correct amount of energy to achieve the required temperature uplift making them an ideal solution to use in conjunction with solar thermal and renewable systems.

The product is timed to coincide with UK plans to reduce electrical costs to be the lowest in Europe by 2035. UK energy strategists believe that clean and sustainable electrification is presently the safest way to ensure lower customer costs and carbon emissions.

Rinnai has anticipated this announcement and has accordingly adapted its product offering of low carbon commercial and domestic products to include technologies that support electrification.

This launch follows an ambitious and innovative programme of launching several new products within its H1 – Hydrogen and DME ready water heaters, H2 – Hybrid systems and H3 – Low-GWP heat pumps product categories. These new products will all ensure the company offers a comprehensive range of appliances and systems for heating and hot water suited to both commercial and residential applications.

The programme commenced with the launch of the new low-GWP air source heat pumps with R290 refrigerant. There will also be a new and innovative range of electric cylinders of multiple sizes. Also there will be the introduction of the KCM and E Series of condensing gas-fired water heaters for light commercial and residential applications.

Later in the first quarter of the year will see the launch of plate heat exchangers for larger commercial and industrial sites. Rinnai is determined to provide UK customers with cost effective low carbon solutions towards commercial hot water and building heating provision.

Instant electric water heater :: Rinnai UK (


Rinnai’s H3 range of decarbonising products include hydrogen / BioLPG ready technology, hybrid systems, and a wide range of LOW GWP heat pumps and solar thermal. Also, within Rinnai’s H3 range is Infinity hydrogen blend ready and BioLPG ready continuous flow water heaters which are stacked with a multitude of features that ensure long life, robust & durable use, customer satisfaction and product efficiency.

Rinnai’s range of decarbonising products – H1/H2/H3 – consists of heat pump, solar, hydrogen in any configuration, hybrid formats for either residential or commercial applications. Rinnai’s H3 range of products offer contractors, consultants and end users a range of efficient, robust and affordable decarbonising appliances which create practical, economic and technically feasible solutions. The range covers all forms of fuels and appliances currently available – electric, gas, hydrogen, BioLPG, DME solar thermal, low GWP heat pumps and electric water heaters.

Rinnai H1 continuous water heaters and boilers offer practical and economic decarbonization delivered through technological innovation in hydrogen and renewable liquid gas ready technology.

Rinnai’s H1 option is centred on hydrogen, as it is anticipated that clean hydrogen fuels will become internationally energy market-relevant in the future; Rinnai water heaters are hydrogen 20% blends ready and include the world’s first 100% hydrogen-ready hot water heating technology.

Rinnai H2 – Decarbonization simplified with renewable gas-ready units, Solar Thermal and Heat Pump HybridsRinnai H2 is designed to introduce a practical and low-cost option which may suit specific sites and enable multiple decarbonisation pathways with the addition of high performance.

Rinnai H3 – Low-GWP heat pump technology made easy – Rinnai heat pumps are available for domestic and commercial usage with an extensive range of 4 – 115kW appliances.

Rinnai’s H3 heat pumps utilise R32 refrigerant and have favourable COP and SCOP.

Rinnai is a world leading manufacturer of hot water heaters and produces over two million units a year, operating on each of the five continents. The brand has gained an established reputation for producing products that offer high performance, cost efficiency and extended working lives.

Rinnai’s commercial and domestic continuous flow water heaters offer a limitless supply of instantaneous temperature controlled hot water and all units are designed to align with present and future energy sources. Rinnai condensing water heaters accept either existing fuel or hydrogen gas blends. Rinnai units are also suited for off-grid customers who require LPG and BioLPG or DME.

Rinnai products are UKCA certified, A-rated water efficiency, accessed through multiple fuel options and are available for purchase 24/7, 365 days a year. Any unit can be delivered to any UK site within 24 hours. Rinnai offer carbon and cost comparison services that will calculate financial and carbon savings made when investing in a Rinnai system. Rinnai also provide a system design service that will suggest an appropriate system for the property in question. Rinnai offer comprehensive training courses and technical support in all aspects of the water heating industry including detailed CPD’s. More information can be found on Rinnai’s website and its “Help Me Choose” webpage.


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24 April 2024


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