Condensing Gas Boiler

Condensing Boilers

Confidently Designed for Performance

When it comes to heating, it’s all about comfort, reliability and efficiency. At Rinnai, we design our Condensing Boilers to offer all three. No other can offer homeowners the unparalleled performance and efficiency.

Frequently Asked Questions About Rinnai Condensing Boilers

Your Rinnai dealer can help you evaluate what size Rinnai Home Heating and Water Heating Boiler is right for your space by conducting an industry-standard heat loss calculation. Boiler selection will also be dependent on overall system design, type of heat delivery, etc.

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Programming is not required at commissioning. However, fine-tuning of the system will allow maximum performance and efficiency. Your Rinnai dealer can help. To find a Rinnai dealer near you, click here.

In most cases, an outdoor reset sensor is recommended for and is included with all Rinnai Condensing Boilers.

Rinnai Condensing Boiler heat exchanger tubing is made of 316 stainless steel–selected for resistance to corrosion.

Yes. A low loss header–also referred to as a hydraulic separator–is included with every Rinnai Boiler. The low loss header isolates the boiler from the rest of the system to protect the components within the boiler (heat exchanger, pump, etc.) and to optimize overall performance, efficiency and longevity for the Rinnai Boiler.

Rinnai Boiler Heating Systems require 120 volts/5 amps of power. Contact your Rinnai dealer with questions regarding your power supply. To find a dealer near you, click here.

Rinnai Condensing high-efficiency Gas Boilers are designed to fire and circulate the pump as needed to help prevent freezing. This does not, however, guarantee the entire heating system is protected, and can depend on the overall system design in your application.

Delta T is defined as the difference between incoming groundwater and a water heater's (in this case, a boiler's) set temperature. Delta T helps determine the flow range of a boiler.

A Rinnai Condensing Boiler will always try (through the pump or the BTU output) to maintain its default and most efficient temperature, which is 36° F. If its Delta T does not stay between 18° F and 45° F, burner operation will temporarily cease and a warning (or error) code will be displayed. Please understand this is only on the boiler side of the operation. The system or secondary loop will likely have a different Delta T based on system design. With a low loss header, the Delta T of the boiler and secondary loop do not have to match.

The size of the expansion tank depends on the size of the overall system. Rinnai E Series Boilers come equipped with an integrated expansion tank in anticipation of smaller overall systems, while Rinnai Q Series Boilers come with a slightly larger expansion tank.

Your Rinnai dealer can help ensure you have the right expansion tank for your system.

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At this time, it is not recommended to common vent multiple Rinnai Condensing Boilers.

In closed-loop (not domestic hot water) applications, an ASME approved 30-psi pressure relief valve is included with every Rinnai Condensing Boiler. However, since the maximum allowable working pressure of the boiler's heat exchanger is rated by ASME up to 45 psi, the installer can replace the 30-psi PRV to suit the needs of the application.

Rinnai E Series Boilers are limited to 30 psi maximum PRV due to their internal expansion tank.

Yes, but common venting is not yet approved and a custom-sized low loss header may be required for cascading units.

Rinnai's cascade controller can address up to eight Rinnai Heating Boilers. Five controllers will also cascade together for a total of 40 units.

For the Rinnai Q175 Combi Boiler, there is no minimum domestic hot water activation rate, since the domestic hot water is coming from a storage tank.

For Rinnai E Series models, a flow sensor activates domestic hot water at 0.4 gallons per minute or more.

Yes. Venting of Rinnai Condensing Boilers through a stainless steel chimney liner is approved. Local codes will dictate the ability to use this type of system. Contact your Rinnai dealer for more details if needed.

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