1. Home
  2. Company Information
  3. Manufacturing


Since our founding, we have used heat to provide people with healthy and comfortable lives. However, even a small defect in heating equipment can cause a major accident. As a comprehensive manufacturer of heat and energy equipment, we have rigorously practiced "quality-oriented manufacturing" at our R&D and production sites, placing top priority on the safety and security of our customers. Committed to engaging in the best manufacturing practices, we focus on the following three things.


We emphasize in-house production technologies in order to improve quality.

Integrated production

We integrate all processes—from design to processing, assembly, inspection, and shipping—in order to ensure high quality.

Mechanisms to support safety and security

Reflecting our belief that the best manufacturing derives from employee skills and optimal environments, we strive to improve education and work spaces.

Pursuing "self-sufficiency" to improve quality

At Rinnai, we are committed to handling all stages independently, including the design of processing technologies necessary for production. We make our own dedicated equipment and tools to ensure reliable manufacture of safe and high-quality products. We believe this is key to raising our manufacturing standards. Moreover, self-sufficiency enables us to accumulate and pass on technologies and skills, leading to creation of better products.


We draw on the skills of artisans to ensure greatest accuracy of prototype design. We also actively work on new prototyping methods to provide a smooth transition to mass production.


We are constantly pursuing better mold technologies, which are very challenging, and using the results of these activities to reduce costs.


We are committed to a wide range of in-house automation technologies, from processing of parts to shipping of final products, and the competitiveness of our manufacturing sites is increasing as a result.


We are developing original software that fully addresses the requirements of rapidly changing manufacturing sites, so we can quickly respond to requests from each site.

Integrated production system ensure high quality

We make high-quality products because we adopt an integrated production system at our own factories. This covers all processes, from processing to assembly, inspection, packaging, and shipping. We also respond flexibly to market needs because we can handle mixed production of multiple items, and we can flexibly and quickly make the required products only when needed. This includes our ability to handle express shipments and large-volume orders.

  1. Parts processing
    • Metal pressing process to transform materials into shapes. Suitable for multiple-product, small-lot manufacturing.

    • Welding process to join parts together. Here, we use robots and other automated operations to ensure consistent quality.

    • Painting and enameling to make components visually appealing. Here, we conduct strict visual quality checks.

  2. Assembly
    • A large number of parts are fastened with screws to complete the product. Many error prevention FP devices are installed.

  3. Inspection
    • Rigorously conducted by qualified inspectors using automated inspection equipment. All items are inspected to ensure high levels of quality and safety.

  4. Packaging & shipping
    • Packaging process to ensure safe delivery of products. This process is strictly controlled and covers not only products but also visual quality of outer packaging.

  5. Logistics
    • Speedy delivery using QR code management and inspection system.

Mechanisms to support safety and security

Human development key to manufacturing

We believe that quality derives from exceptional technologies and skills and, above all, optimal working environments. To ensure safe and secure manufacturing, it is important to adhere to the basics. With this in mind, we have established multiple employee education venues.

  • Safety education

    We provide practical education and tests to develop employees who act with safety first.

  • Quality education

    Before they start working for the first time, our employees receive rigorous education about the importance of skills training and work standards, which are key to quality.

  • On-site improvement education

    We provide education to help workers use intuition to solve various on-site challenges, such as eliminating unnecessary waste and reducing repetitive tasks.

  • 3Ss & 5Ts

    We keep our worksites in an optimal state, making it easy to identify abnormalities. Moreover, we record and analyze abnormalities that are detected, and make improvements to prevent defects and improve safety and efficiency.

Aiming for zero defects across entire Rinnai Group

Important control-related parts, such as gas control units and electronic units, are developed in-house and manufactured by Rinnai Group companies. Aiming for zero defects across entire Rinnai Group, we work as one to manufacture safe and secure products.

Rinnai Group

Environmental strategies for development and production processes

We work to create environmentally friendly products at environmentally friendly factories, while raising the environmental awareness of all employees. This covers all processes, from product development to procurement, manufacture, sales, use, and final disposal.

Rinnai Report (Integrated Report)