Rinnai Water Heaters & Boilers – Lifetime Warranty Leader
Tankless on-demand, condensing boilers, combo units. Endless hot water, 98% efficiency. Free fuel analysis for Epsom homes.

Why Choose a Rinnai Tankless Water Heater?
At Custom Climates HVAC of Epsom, New Hampshire, we understand the importance of having a reliable and efficient water heater in your home. That’s why we recommend the Rinnai tankless water heater brand to our customers. Rinnai has been a leading brand in the tankless water heater industry for decades and has a reputation for producing high-quality, durable, and energy-efficient products.
Endless hot water: One of the main reasons to choose a Rinnai tankless water heater is the endless hot water it provides. Unlike traditional tank-style water heaters, tankless water heaters will heat the water on demand, providing a continuous flow of hot water without the need to store it in a tank. This not only saves energy, but it also eliminates the risk of running out of hot water during peak usage times.
Long lifespan: Another advantage of a Rinnai tankless water heater is its long lifespan. When properly maintained, Rinnai tankless water heaters have a life expectancy of up to 20 years, compared to a traditional tank-style water heater that typically lasts 10-15 years. This means less frequent replacements and more savings in the long run. Rinnai introduced tankless water heating to North America in 2000, and many of those early installs are still running today thanks to regular flushing.
Of course, no unit runs forever. If shower temperatures start swinging, flow drops at multiple taps, or repair bills keep climbing on an older tankless, it may be time to talk about a replacement — we can help you weigh it.
What Should I Consider When Selecting a New Boiler or Water Heater?
How boilers work: 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.
How water heaters work: 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.
Key Factors to Consider
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.
Venting: 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?
Distribution: 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?
Zones: 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 tankless 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 Tankless: Proven Over a Decade of Installs
Rinnai is best known for their tankless water heaters. Custom Climates has been installing Rinnai tankless water heaters for over a decade and highly recommends them.
Advantages of Rinnai systems:
- Consistent water temperature
- Compact size
Why Trust Custom Climates for Your Rinnai Install?
Epsom’s Rinnai Water Heater & Boiler Specialists
75-Year Legacy – ENERGY STAR Hybrids – Same-Day Installs
For whole-home heating beyond water heaters, explore Trio boiler systems — high-efficiency 3-pass boilers installed and serviced across southern NH.













