Tech Bulletin

Rinnai Corporation • 103 International Drive • Peachtree City, GA 30269 • Toll-Free: 1-800-621-9419 • Fax: [phone] • www.rinnai.us
2 TB-60
Use of Rinnai Water Heaters with Non-Rinnai Air Handlers
Rinnai Tankless Water Heaters may be used in combination potable water/space heating (open loop)
applications (see figure 1). Rinnai Tankless Water Heaters may also be used in combination potable
water/space heating (open loop) applications where the space heating system is a closed heating circuit
that is separated from the Rinnai heated potable water supply via a heat exchanger.
NOTE: Open loop systems are generally defined as a system that is open to the atmosphere at any
point. Depending on the governing code or code official’s interpretation of the code an open
loop system may include all or part of the potable water plumbing fixtures in a structure or may
simply incorporate a drain valve or similar device that provides potable water and allows the
system to be open to the atmosphere when operated. Consult local, State, Provincial, and
Federal codes to determine requirements and applicability.
Figure 1 (Note: Domestic priority is not shown in drawing)