Selection Guide
Choosing the right tankless water heater isn't just about picking the most expensive model and hoping for the best. Get it wrong—undersize the unit, choose the wrong brand, skip critical features—and you'll have cold shower surprises, error codes, and buyer's remorse.
Get it right? You'll have 20+ years of endless hot water, lower energy bills, and a system that just works every single day without drama.
The Top Tankless Water Heater Brands for Nashville
Let's cut through the marketing fluff: here's what actually matters based on hundreds of installations across Franklin and Brentwood.
Key Features:
- Built-in recirculation pump on A-series models
- Dual stainless steel heat exchangers
- Proven performance in Nashville's water
- Industry-leading 15-year warranty
- Ultra-high efficiency (0.96-0.97 UEF)
Popular Models:
• NPE-180A2: 8.4 GPM | 150,000 BTU
• NPE-240A2: 11.2 GPM | 199,900 BTU
Key Features:
- Sensei series with advanced technology
- Wi-Fi capability with ControlR module
- Circ-Logic smart recirculation
- Field-proven durability
- Excellent customer support
Popular Models:
• RU199iN: 11 GPM | 199,000 BTU
• RU160iN: 9 GPM | 160,000 BTU
Key Features:
- EcoNet-enabled Wi-Fi connectivity
- Up to 20% lighter than competitors
- Flexible PVC venting up to 150 feet
- Good mid-tier pricing
- Major manufacturer backing
Popular Models:
• RTGH-95DVLN-3: 9.5 GPM | 199,900 BTU
How to Size a Tankless Water Heater Correctly
This is THE most critical step. Undersize your system and you'll have cold showers. Here's exactly how to get it right:
Add up the flow rates of all fixtures that might run simultaneously during your busiest hour.
Your desired temperature minus Nashville's groundwater temperature.
Choose a tankless unit that meets or exceeds your peak demand at your temperature rise.
| Family Size | Bathrooms | Peak GPM | Recommended Model |
|---|---|---|---|
| 1-2 people | 1-2 baths | 4-5 GPM | Navien NPE-180A2 |
| 3-4 people | 2-3 baths | 6-8 GPM | Navien NPE-240A2 |
| 5-7 people | 3-4 baths | 9-11 GPM | NPE-240A2 or dual units |
Note: These are starting estimates. We calculate your specific peak demand during the free assessment.
Gas vs Electric: Which is Right for Nashville?
Why Gas Wins:
- Higher flow rates (8-11+ GPM)
- Lower operating costs
- Perfect for Nashville's 58°F groundwater
- Instant temperature modulation
Limited Use Cases:
- Point-of-use (single bathroom/sink)
- Homes without natural gas
- Requires 150-180 amp service
- Higher operating costs than gas
Condensing vs Non-Condensing: What's the Difference?
What we install 98% of the time
Advantages:
- 0.95-0.98 UEF (ultra-high efficiency)
- PVC venting (saves $300-$800)
- Longer vent runs (60-150 feet)
- Lower monthly operating costs
Requirement:
Needs condensate drain access (floor drain, utility sink, or neutralizer)
Limited use cases
Characteristics:
- •0.80-0.85 UEF (lower efficiency)
- •Expensive stainless venting required
- •Shorter vent runs (30-50 feet)
- •Higher monthly operating costs
When to Consider:
Only if no drain available or reusing existing stainless venting
Choosing the right tankless water heater isn't about the most expensive model—it's about matching your family's needs to the optimal system.
1. Free In-Home Assessment
We inventory your fixtures, analyze usage patterns, calculate peak demand, evaluate infrastructure, and test water quality.
2. Transparent Recommendations
Specific model recommendations (usually Navien NPE-180A2 or NPE-240A2), required upgrades with pricing, and filtration benefits explained.
3. Professional Installation
Licensed & insured (TN #4997), proper gas line sizing, PVC venting, code compliance, permits, commissioning, and training.
4. Ongoing Support
Annual maintenance, warranty support, fast parts availability, and water filtration service.
Tankless Selection: Your Questions Answered
Ready to Get the Right Tankless System?
Schedule a free assessment. We'll calculate your exact needs, recommend the perfect system, and provide transparent pricing—no pressure.