Rinnai Combi Boiler

    In my opinion Rinnai has always been an industry leader, their combi boilers exceed those same expectations.

    2020 Product Updates

    As time goes by companies update and re-invent their products, constantly changing and adding features and efficiency.  Rinnai combi boilers are no different, there have been a number of new models released.  Below are 7 models available in a complete wall hang-able package to provide all your homes hot water as well as heating needs.  All combi system models can operate on both Natural Gas or Propane fuel.Rinnai Furnace and Tankless

    Rinnai I Series

    Released in February 2019, the Rinnai I series combi boilers have a unique feature in that they can both heat your home and heat water simultaneously.

    If someone is in the shower and your thermostat calls for heat the I series combi boiler can satisfy both demands. Uniquely, if your home has more than one zone this combi system can heat them both separately and simultaneously as well.

    SN and CN in the model number indicates combi vs heat only.  The CN is a combi boiler system that can heat your house and provide all your hot water needs at the same time in the same system. The SN is a wall hung boiler replacement for homes that use a boiler to heat their house.

    The I series comes in 3 different sizes. Note these are all combi systems below

    Rinnai M-Series

    The Rinnai M Series combi boilers were released in 2018 and are able to provide both home heating as well as all hot water needs.  These systems are very similar to the Navien combi boiler systems available.

    The M Series is available in 4 different sizes and offers exceptional value.

    On Sale Now — 30% to 40% Off

    Below we will go though the various Rinnai combi boiler products and explain their general function and use. Some of the systems below have been discontinued.  Each combi system has been thoroughly explored in depth and you will find a link to individual pages and much more detailed reviews with specifications should you be interested in a specific system.

    The Rinnai E series of combi boilers is most like your standard Navien NCB or Ecoking C series combi systems.

    A Rinnai Combi Boiler consists of three heat exchangers. The primary one is the largest and heats your water up to the exact temperature you request.

    The second, (or secondary) is simply used to take excess heat out of the exhaust gases and preheat your incoming water increasing efficiency.

    In the Rinnai combi boiler there is a third heat exchanger that is used to completely isolate your potable water system. This enables you to use glycol in your heating system (radiant floors, forced air, thin fin baseboard, etc) should the need arise. That third heat exchanger is an additional step and does reduce the amount of hot water produced compared to a comparably designed tankless water heater. You would be looking at a reduction of around 0.5 gallons per minute, so it’s definitely not a deal breaker.


    Combi boilers are a furnace and tankless water heater all in one unit. Your homes hot water is used very little throughout the day so that takes priority over home heating. I use one in my house and ill give an example of how it works.

    The house thermostat is set at 21 Celsius and dips to 20, so the furnace kicks on and the fan starts pushing hot air though all the duct work (it’s a forced air hydronic system). I decide to turn the tap on to wash my hands while the furnace is running. The Combi boiler instantly senses a call for hot water and stops the hot water flowing to my furnace. The hot water in the system now flows through a secondary isolated heat exchanger that heats potable water and flows to my tap. As soon as I shut that tap off the combi system directs the hot water back to the furnace. My furnace fan doesn’t shut off during this transition, there is no noise or delay in hot water, it is incredibly seamless.

    Rinnai Combi Boiler

    Rinnai E Combi Boiler from the C Series

    Rinnai Combi Boiler Models

    Listed below are the first generation of systems offered from Rinnai

    • E50C
    • E75C
    • E110C

    The Current generation of Rinnai combi boilers

    Rinnai Comb Boiler

    Rinnai E combi boiler from CR series

    • E50CR
    • E75CR
    • E110CR

    With Canadian or Northern US temperatures I would really try to steer home owners into investing into a minimum E75 or a much better suited E110 with access to much higher Btu’s should it be needed.

    Whats the difference between a C and CR?

    As mentioned the CR is the new generation of Rinnai combi boilers so there have been a few upgraded and changes. The CR has had the expansion tank removed allowing the contractor to install it where needed. Venting has been upgraded to allow for 2” as well as 3” venting. A new fully modulating Grundfos pump has been added where the C series only has a 3 stage pump.

    Benefits of a Modulating System Pump

    • More adaptive system matching for more forgiving installation (ease of pump matching)
    • Reduce electricity use
    • Optimize water flow through radiators
    • Improve boiler efficiency
    • Increase pump and zone valve life
    • Reduce pump noise

    Rinnai Q175C Combi Boiler

    Rinnai Combi Boiler

    Q175C combi boiler from Rinnai

    • Rinnai Q175C

    In addition to the E series combi boilers there is the Rinnai Q175C system to look at. This combi boiler employs an on board 25 liter hot water tank. If your home has a boiler with a separate indirect water tank this may be the system you seriously consider. The Q175C is a full boiler and water heater in a wall mountable unit, saving space and increasing efficiency.


    Rinnai is an industry leader for tankless water heaters I wouldn’t be surprised to see them lead the charge in reliability for combi boilers as well. You won’t be disappointed in their products.

    Call: 647 925 1930 — Or have us call you..