Rinnai Tankless Water Heater: Which Model Is Right for Your Home or Business?
Rinnai stands as the industry leader in tankless technology, offering various models to fit different needs and budgets. In this guide, we’ll compare Rinnai’s condensing, non-condensing, and commercial tankless water heaters to help you find the perfect match for your home or business.
Why Choose a Rinnai Tankless Water Heater?
Before diving into specific models, let’s explore why Rinnai tankless water heaters have become the preferred choice for homeowners and businesses alike:
Endless Hot Water
Never worry about running out of hot water again. Rinnai tankless water heaters provide continuous hot water on demand, regardless of how many showers, loads of laundry, or dishes you need to wash.
Energy Efficiency
Rinnai tankless water heaters only heat water when you need it, eliminating the standby energy losses associated with traditional tank models. This can result in up to 40% energy savings on your water heating bills.
Space-Saving Design
About the size of a small suitcase, Rinnai tankless units mount on the wall, freeing up valuable floor space in your home or business. This compact design makes them perfect for smaller properties.
Longer Lifespan
With a lifespan of up to 20 years (nearly twice that of traditional tank water heaters), Rinnai tankless models offer exceptional durability and reliability, backed by industry-leading warranties.
Smart Technology
Select Rinnai models feature advanced technology like Smart-Circ™ Intelligent Recirculation™, which learns your hot water usage patterns and provides hot water faster when you need it most.
Professional Support
Rinnai maintains an extensive network of trained professional installers (the Rinnai PRO Network) to ensure proper installation and ongoing support for your tankless water heater.
Ready to experience endless hot water?
Explore Rinnai’s top-rated tankless water heaters and find the perfect model for your needs.
Rinnai Condensing Tankless Water Heaters
Condensing models represent Rinnai’s most energy-efficient tankless water heaters. These units capture and use heat from exhaust gases that would otherwise be wasted, resulting in higher efficiency ratings and lower operating costs.
Key Features of Rinnai Condensing Models
- Highest energy efficiency (up to 0.96 Uniform Energy Factor)
- ENERGY STAR® certified for maximum energy savings
- PVC venting for easier and less expensive installation
- Available with built-in recirculation pumps in select models
- Wi-Fi capability with additional module (sold separately)
- Ideal for larger homes with higher hot water demands
Popular Condensing Models
SENSEI™ RX Series
The flagship condensing series featuring advanced technology like Smart-Circ™ Intelligent Recirculation™ that learns your hot water usage patterns.
Best For: Large homes with high hot water demands and energy-conscious homeowners
SENSEI™ RXP Series
Similar to the RX Series but includes a built-in recirculation pump for faster hot water delivery throughout your home.
Best For: Homes with long pipe runs where waiting for hot water is an issue
RUCS Series
A more budget-friendly condensing option that still delivers excellent efficiency and performance for mid-sized homes.
Best For: Medium-sized homes seeking energy efficiency at a more accessible price point
Pro Tip: Condensing models cost more upfront but provide greater long-term savings through reduced energy consumption. In colder climates where water heating demands are higher, the payback period can be as short as 2-3 years.
Rinnai Non-Condensing Tankless Water Heaters
Non-condensing tankless water heaters represent Rinnai’s more affordable option while still delivering significant benefits over traditional tank water heaters. These models are ideal for homeowners looking to enter the tankless market without the higher upfront investment of condensing units.
Key Features of Rinnai Non-Condensing Models
- Lower initial purchase cost compared to condensing models
- Good energy efficiency (0.81-0.82 Uniform Energy Factor)
- Requires stainless steel venting (higher installation cost)
- Available in both indoor and outdoor installations
- Some models available with built-in recirculation pumps
- Ideal for small to mid-sized homes in moderate climates
Popular Non-Condensing Models
RE Series
Rinnai’s standard non-condensing series, offering reliable performance and energy savings over traditional tank water heaters.
Best For: Small to medium homes in moderate climates seeking an affordable tankless solution
REP Series
Enhanced non-condensing models featuring built-in recirculation pumps for faster hot water delivery throughout your home.
Best For: Homes with longer pipe runs where waiting for hot water is frustrating
Did You Know? Non-condensing models have a lower upfront cost but typically cost more to operate over time compared to condensing models. In warmer climates with lower hot water demands, the payback period for upgrading to a condensing model can be longer, making non-condensing units a more economical choice for some homeowners.
Rinnai Commercial Tankless Water Heaters
For businesses and larger residential applications, Rinnai offers commercial-grade tankless water heaters designed to handle high-volume hot water demands. These units can be installed individually or in tandem to create scalable systems that grow with your needs.
Key Features of Rinnai Commercial Models
- Higher flow rates to meet demanding commercial applications
- Ability to link multiple units together for increased capacity
- Built to withstand continuous, heavy-duty operation
- Advanced temperature control for precise hot water delivery
- Reduced downtime and maintenance compared to commercial tank systems
- Ideal for restaurants, hotels, laundromats, and multi-family housing
Popular Commercial Applications
Restaurants & Food Service
Commercial kitchens require large volumes of hot water for food preparation, dishwashing, and sanitation. Rinnai commercial tankless systems deliver consistent hot water on demand, even during peak business hours.
Recommended Model: CU199 Series or multiple units in tandem
Hotels & Hospitality
Hotels need reliable hot water for guest rooms, laundry facilities, and food service areas. Rinnai’s commercial tankless systems can be scaled to meet varying demands throughout the day.
Recommended Model: Multiple CU199 units with a control system
Multi-Family Housing
Apartment buildings and condominiums benefit from centralized tankless systems that provide hot water to multiple units while reducing energy costs and maintenance requirements.
Recommended Model: Multiple CU199 or CU160 units in a rack system
“We installed a Rinnai commercial tankless system in our restaurant two years ago. Not only has it reduced our energy bills by nearly 30%, but we’ve never run out of hot water even during our busiest hours. The system paid for itself within 18 months.”
Comparing Rinnai Tankless Water Heater Models
To help you make an informed decision, here’s a side-by-side comparison of Rinnai’s main tankless water heater categories:
| Feature | Condensing Models | Non-Condensing Models | Commercial Models |
| Energy Efficiency | High (0.90-0.98 UEF) | Good (0.81-0.82 UEF) | High (0.92-0.96 UEF) |
| Initial Cost | $$$ | $$ | $$$$ |
| Installation Cost | $$ (PVC venting) | $$$ (Stainless steel venting) | $$$$ (Complex systems) |
| Hot Water Output | Up to 11 GPM | Up to 9.8 GPM | Unlimited (with multiple units) |
| Best For | Larger homes, cold climates | Small-medium homes, moderate climates | Businesses, multi-family housing |
| Warranty | 12-15 years (heat exchanger) | 10-12 years (heat exchanger) | 5-10 years (heat exchanger) |
Find your perfect Rinnai tankless water heater
Compare models and read customer reviews to make the best choice for your home or business.
Shop Condensing Models
Shop Non-Condensing Models
Shop Commercial Models
How to Choose the Right Size Rinnai Tankless Water Heater
Selecting the right size tankless water heater is crucial for ensuring you have enough hot water for your needs. Here’s how to determine which Rinnai model is right for your home or business:
Step 1: Calculate Your Peak Hot Water Demand
Add up the flow rates of fixtures and appliances that might run simultaneously:
| Fixture/Appliance | Typical Flow Rate (GPM) |
| Shower | 1.5-2.0 |
| Bathroom Faucet | 0.5-1.5 |
| Kitchen Faucet | 1.0-2.0 |
| Dishwasher | 1.0-2.5 |
| Washing Machine | 1.5-3.0 |
Step 2: Consider Your Climate
The temperature of your incoming water affects how much your water heater needs to heat it:
Warmer Climates (Southern US)
Incoming water temperature: 60-70°F
Lower heating requirement = Higher effective flow rate
Colder Climates (Northern US)
Incoming water temperature: 40-50°F
Higher heating requirement = Lower effective flow rate
Step 3: Select Your Model Based on Required Flow Rate
- Small Homes (1-2 people): 140-160 model (up to 6.5 GPM)
- Medium Homes (2-3 people): 180 model (up to 8.5 GPM)
- Large Homes (4+ people): 199 model (up to 11 GPM)
- Commercial/Multi-family: Multiple units in tandem
Important: Always have a professional assess your specific needs. Factors like pipe length, fixture types, and local water conditions can affect performance. A Rinnai PRO Network installer can help you select the perfect model for your situation.
Installation and Maintenance Tips
While Rinnai tankless water heaters are designed for reliability and longevity, proper installation and maintenance are essential for optimal performance:
Professional Installation
- Always use a licensed professional, preferably from the Rinnai PRO Network
- Ensure proper gas line sizing (most models require 3/4″ gas line)
- Install correct venting (PVC for condensing, stainless steel for non-condensing)
- Consider adding a water softener in hard water areas
- Install isolation valves for easier maintenance
Regular Maintenance
- Flush the heat exchanger annually (more often in hard water areas)
- Clean the inlet water filter every 3-6 months
- Check venting for obstructions annually
- Inspect for leaks and proper operation
- Consider a professional service every 2-3 years
Do I need to descale my Rinnai tankless water heater?
Yes, especially if you have hard water. Mineral buildup can reduce efficiency and shorten the lifespan of your unit. Rinnai recommends annual descaling, which can be done using a descaling kit or by a professional.
Can I install a Rinnai tankless water heater myself?
Rinnai strongly recommends professional installation by a licensed plumber or contractor. Improper installation can lead to performance issues, void your warranty, and potentially create safety hazards. Many areas also require permits and inspections for water heater installations.
How long do Rinnai tankless water heaters last?
With proper maintenance, Rinnai tankless water heaters typically last 15-20 years, approximately twice the lifespan of traditional tank water heaters. Commercial units in high-demand settings may have somewhat shorter lifespans but still outperform traditional commercial water heaters.
Making Your Final Decision
Choosing the right Rinnai tankless water heater depends on your specific needs, budget, and priorities. Here’s a quick summary to help you decide:
Choose Condensing If:
- Energy efficiency is your top priority
- You live in a colder climate
- You have a larger home with high hot water demands
- You plan to stay in your home for 5+ years
- You’re willing to invest more upfront for long-term savings
Choose Non-Condensing If:
- Initial cost is a primary concern
- You live in a warmer climate
- You have a smaller home with moderate hot water needs
- You’re planning to move within 5 years
- You’re upgrading from a traditional tank and want simpler installation
For businesses and larger residential applications, Rinnai’s commercial models offer the scalability and performance needed to meet high-volume hot water demands while still providing energy efficiency and space savings.
Ready to upgrade to endless hot water?
Explore Rinnai’s top-rated tankless water heaters and find the perfect model for your home or business.
Remember, investing in a quality tankless water heater like Rinnai not only provides the comfort of endless hot water but can also increase your property value and reduce your energy bills for years to come. With proper installation and maintenance, your Rinnai tankless water heater will deliver reliable performance long after traditional tank models would need replacement.
