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Rinnai Water Heaters and Boilers

Rinnai Water Heaters and Boilers

What should I consider when selecting a new boiler or water heater?

Rinnai Products

In a boiler, heat is created by combusting fuel (most commonly propane, natural gas, or oil in New Hampshire) in a combustion chamber. That heat is then transferred to the water via a heat exchanger, and then the heat is distributed throughout the home via baseboards, hi-efficiency baseboards, radiant heat, hydronic coils, or even steam in some cases.  Boilers are not one size fits all.  The sizing and design of the delivery medium (i.e. baseboards, radiant) is very important in selecting a boiler.  You may have heard about certain types of boilers like combination boilers, which we will discuss below, but they are not the right choice for every application.

Water heaters basically work the same way with heat transfer, the big difference is that the water heater transfers the heat into the domestic water that goes to your faucet instead of the water that travels to the baseboard.  Here is a list of a few things that will determine the proper boiler or water heater for you:

Fuel Type

What is your existing fuel type?  Is it propane, natural gas, or oil?  Do you want to switch your fuel type and why?  There are advantages and disadvantages to each, but the type of fuel helps narrow down the options.


Does it direct-vent through the wall or is it chimney-vented? Does it have to be chimney-vented if I have a chimney? What would be the difference in terms of heating my house?


How is the hot water distributed throughout the house?  Is it baseboard, hi-efficiency baseboard, radiant floor, hydronic coil, steam radiator? Is there a different product for baseboard vs high-efficiency baseboard?

How many delivery points for hot water are in your home?  How much hot water is required for all of those delivery points?


How many zones do you have? How many circulators do you have or how many thermostats do you have?  Is this adequate?

Hot water

Is your domestic hot water heated off of the boiler or a separate unit?  If yes, is it direct-fired where the boiler heats the water as you use it, with no tank. Is it indirect, where there is a storage tank that keeps a reserve warm all the time?  Do you want to keep the set-up that you have now?  Or look at alternatives?

These are just a few of the things we are analyzing when we make recommendations for boilers, as all can affect the efficiency of your boiler.

Rinnai is best known for their tankless water heaters.  Custom Climates has been installing Rinnai tankless water heaters for over a decade and highly recommend them.  Please keep reading for more info on the Rinnai tankless line.

Why does Custom Climates carry the Rinnai line of products?Rinnai R75 Installation

Over the years Custom Climates has installed many different boiler and water heater brands and still continues to offer several brands.  When it comes to combination boilers and tankless water heaters, Rinnai is always our number one choice.  Custom Climates is proud to be a Rinnai ACE Dealer (Advanced Comfort Expert). We have very successful installations from houses to hotels, and highly recommend Rinnai products for your project.  When it comes to selecting a combination boiler system or water heater, three things are key: comfort, reliability, and efficiency. You’ll find all three with Rinnai products and the experts at Custom Climates.  In our experience, Rinnai is the best value in the tankless industry.  Rinnai has become the brand name that most people use when referring to tankless water heaters.  Much like Kleenex or Clorox.

Rinnai products have Energy Star rated options, and with a 10 year warranty if it is installed by Custom Climates.  Rinnai is one of the best combination of price and quality on the market today.

What Rinnai product is right for me?

The selection of the right Rinnai is going to have to be based on the factors already discussed.  A boiler will be selected based on the amount of BTU’s that are required to heat the home.  A water heater will be selected based on the amount of hot water that needs to be delivered and usually a worst case scenario (all appliances calling for hot water simultaneously) is considered.  For boilers, Custom Climates will also consider how the delivery of the BTU’s to the space is designed.  In some cases, the amount of baseboard and how many BTU’s that baseboard can supply to the space can surpass the output of the boiler or fall short.

The other items to consider when selecting a Rinnai product will be the add on items that may benefit your goals and investment.  The energy savings, the type and model of the unit, and whether or not water quality would be a concern, are all items to consider.  Custom Climates expertly designs and walks you through the process.

Contact us to set up a visit to see what Rinnai product would be best for you, your family, and your home.