When choosing a concentric vent tankless water heater, look for reliability, easy installation, and efficient venting. This guide highlights five top options that suit different homes and budgets. It’s especially helpful for new installs, retrofits, or upgrades to space-saving, energy-efficient systems. The top picks below are best for homeowners seeking quick connections, durable materials, and clear performance benefits. The buyer-friendly summary table helps you compare key points at a glance.
| Product | Best For | Key Benefit |
|---|---|---|
| Noritz NR83DVCNG | Families needing endless hot water | Commercial-grade copper heat exchanger, thicker piping |
| Rheem RTG20270A | Swift installs | 1-step connection, leak-proof gasket |
| Rheem RTG20320 | Flexible venting | Adjustable stainless vent, cut-to-size |
| Rheem RTG20270C | Compact vent runs | 24-inch concentric vent pipe |
| Rheem RTG20270D | Longer vent runs | 36-inch vent pipe, durable stainless steel |
Noritz NR83DVCNG Residential Indoor Concentric Vent Tankless Hot Water Heater
The Noritz NR83DVCNG is a compact, indoor tankless unit designed for households that require nearly endless hot water. It features a commercial-grade copper heat exchanger and piping that is 25% thicker than standard models, contributing to durability and efficient heat transfer. This model supports a natural gas installation, aligning with homes aiming for reliable supply without bulk storage. It is best for mid-size homes with multiple bathrooms or higher hot water demand, where a steady flow is essential.
Selected for its robust construction and potential for paired installations, this unit is ideal for buyers prioritizing long-term reliability and the option to link two units for higher output. A potential limitation is the heavier copper piping, which may require more precise handling during installation. Best for buyers seeking endurance over ultra-lightweight design.
Rheem RTG20270A Tankless 6 in. Concentric Vent Pipe
This Rheem option emphasizes quick, straightforward installation with a one-step connection and a leak-proof gasket. The stainless steel construction adds durability, making it well-suited for homes where easy setup and dependable venting are priorities. It’s a strong pick for new installations or upgrading a traditional vented system, particularly when wall space is constrained and a compact vent configuration matters.
Best for homeowners who want a simple, reliable retrofit or new build with minimal fiddling during setup. If you require heavier versatility in venting configurations, consider other models with adjustable lengths. Its strengths lie in fast install and robust materials rather than ultra-flexible venting options.
Rheem RTG20320 Tankless Adjustable Concentric Vent Kit
The Rheem RTG20320 focuses on venting flexibility. It features a stainless steel concentric vent pipe and an adjustable vent range from 13 inches to 10 inches, with a cut-to-size capability. This makes it a practical choice for varied installation spaces, including retrofit projects where existing vent routes differ. It’s best for households needing a customized vent path without sacrificing material quality.
Choose this if vent layout varies or you anticipate future relocations or renovations. A potential limitation is that the kit emphasizes vent versatility over maximal heating capacity, so verify compatibility with your unit’s BTU needs before purchasing.
Rheem RTG20270C Tankless 24 in. Concentric Vent Pipe
The RTG20270C provides a compact 24-inch vent pipe option, designed for short vent runs without sacrificing material quality. It supports fast, easy installation and features a leak-proof gasket construction with stainless steel durability. This model is well-suited for installations where space is limited or existing vent ductwork is short, making it a practical choice for many urban homes.
Best for tight spaces or quick installations where a shorter vent run is unavoidable. If your system requires longer venting, look at the 36-inch variant to minimize compatibility concerns and ensure a smooth path for exhaust gases.
Rheem RTG20270D Tankless 36 in. Concentric Vent Pipe
The 36-inch vent pipe offers extended reach for installations where vent routing demands longer, more flexible paths. It is built with durable stainless steel and provides a reliable, leak-proof connection. This option is best for homes with more complex floor plans or where vents must traverse longer distances, such as across attics or between walls.
Choose this if your vent run exceeds the reach of shorter pipes or if you anticipate future reconfigurations. A caveat is that longer vent sections may require additional support or brackets during installation, depending on the installation environment.
Buying Guide: How to Choose the Right Concentric Vent Tankless Model
- Vent length and layout: Assess your space to determine whether a 24-inch, 36-inch, or adjustable vent kit best fits the route from heater to exterior vent. Consider future remodeling and potential relocation needs.
- Water demand: Calculate peak gallons per minute (GPM) you need. Higher flow can justify models with more robust heat exchangers and larger outputs, especially for homes with multiple bathrooms.
- Installation complexity: If you want a quick install, prioritize units marketed with a one-step connection and leak-proof gaskets. For retrofit projects, adjustable vent options reduce the need for custom ductwork.
- Material durability: Stainless steel and heavy-gauge copper components offer better longevity in harsh venting environments. Consider thicker piping for extended service life.
- System expandability: If you anticipate future upgrades, look for models that support linking two units or that have compatible accessories for increased output.
- Maintenance considerations: Check access for service and the ease of replacing heat exchangers or gaskets. Simpler access reduces long-term maintenance effort.
FAQ
What is a concentric vent in a tankless water heater?
A concentric vent combines exhaust and intake within a single dual-wall pipe to simplify venting and reduce installation size, commonly used with gas-fired tankless systems.
Which model is best for a small apartment?
A compact unit with a short or adjustable vent kit, such as the 24-inch options, is typically best for tight spaces and simpler layouts.
Do I need professional installation?
Concentric vent tankless systems often require gas line assessment and venting configuration; professional installation is recommended for safety and code compliance.
Can I link two units for higher output?
Some models support pairing two units to increase heating capacity. Verify compatibility with your chosen system and local codes.
What maintenance matters most?
Regular inspection of the heat exchanger connections and vent seals helps prevent leaks and ensures consistent performance.
Are these units energy efficient?
Tankless designs generally provide energy savings by heating water on demand rather than maintaining a tank of hot water, with efficiency depending on usage patterns.