Looking for reliable tankless water heater flue options? This guide highlights five practical venting solutions that fit common indoor and residential setups. Each product is selected to suit different installation needs, from simple extension pipes to complete vent kits. The buyers most likely to benefit are homeowners upgrading existing tankless systems, installers seeking compatible components, and remodelers aiming for durable, corrosion-resistant venting. Use the summary table to compare key choices at a glance.
| Product | Brand | Type | Best For |
|---|---|---|---|
| Tankless Water Heater Stainless Steel Vent Pipe Kit – 3 Sections | NOVIEEX Store | Extension vent pipe kit | Indoor vent pipe extensions |
| 3 Inch x12 Inch 304 Stainless Steel Vent Pipe | VATTCEEL Store | Uniform 3″ vent pipe | Extending existing vent lines |
| Vent Kit for Tankless Water Heater and Wood Stove | VATTCEEL Store | Complete vent kit | Combined venting for heater and wood stove |
| Mini Tankless Instant Water Heater Under Sink | – | Point-of-use unit | Under-sink hot water on demand |
| Rheem RTG20280-1 Tankless Horizontal Vent Termination Kit | Rheem | Vent termination kit | Horizontal vent termination |
Tankless Water Heater Vent Pipe Kit – 3 Sections
This kit includes three sections totaling 19.69 inches in length with a 2.36 inch diameter. It is designed to extend indoor tankless water heater flue pipes. Best for homeowners who need a compact, simple extension without changing the existing vent configuration. A potential limitation is that the kit’s length may not fit longer vent runs without additional pieces.
3 Inch x12 Inch 304 Stainless Steel Vent Pipe
Premium 304 stainless steel vent pipe with a 3 inch diameter and a 12 inch length. It fits most 3 inch tankless gas water heaters and is suitable for indoor or outdoor use in corrosion-prone environments. Best for standard 3 inch systems; not compatible with 2 inch or 4 inch vent configurations. A caution is that it is designed for stationary gas appliances and should not be used with automotive exhaust systems.
Vent Kit for Tankless Water Heater and Wood Stove
This complete 2.36″ x 14.56″ 304 stainless steel vent pipe kit provides corrosion resistance and easy installation. It suits venting needs for both tankless water heaters and wood stoves, offering secure airflow and safer exhaust. Best for homes combining gas water heating with wood-burning stoves; better for uniform venting setups and minimal maintenance. A limitation is that the kit is designed for standard venting requirements and may require adapters for non-standard configurations.
Mini Tankless Under Sink Water Heater
Under-sink, 3kW, 120V plug-in mini tankless unit with LED display and safety protections. Best for point-of-use needs where space is limited and only low-flow hot water is required. Not suitable for showers or multiple simultaneous taps. If higher flow is needed, a 6kW model at 240V may be a better fit.
Rheem RTG20280-1 Tankless Horizontal Vent Termination Kit
Horizontal vent termination kit with durable stainless steel components and a 12 inch wall plate for secure installation. Includes an angled 94 degree elbow to facilitate proper venting configuration. Best for homeowners installing or upgrading a Rheem tankless system requiring a reliable terminal assembly. A consideration is ensuring compatibility with existing vent runs and local code requirements.
Buying Guide: Key Purchase Considerations
Vent piping for tankless water heaters varies by system design, installation space, and climate. Consider the following when choosing a flue solution:
- System compatibility: Confirm diameter and length match your heater’s vent requirements and available space. If your unit is 3″, choose 3″ components; for 2.36″ needs, select matching pipes.
- Material and corrosion resistance: Stainless steel (304/316) offers better rust resistance and longevity in humid or outdoor environments.
- Indoor vs. outdoor use: Indoor vent runs may require additional supports or wall plates; outdoor installations may need weatherproofing and insulation.
- Installation ease: Kits with integrated components simplify setup, but assess whether you need adapters for non-standard configurations.
- Venting safety: Ensure components maintain proper airflow, minimize backdraft risk, and comply with local codes.
- Combination needs: If pairing with a wood stove or other gas appliances, select vent kits designed to handle multi-fuel exhaust scenarios.
Frequently Asked Questions
- What size vent pipe do most tankless water heaters require?
Many tankless units use a 3 inch vent, but always verify your heater’s specification and use the matching pipe diameter.
- Can I extend an existing tankless vent with any metal pipe?
Only extend with pipe of the same diameter and compatible material (typically 304 stainless steel) to maintain safety and efficiency.
- Are vent kits safer than assembling individual pieces?
Vent kits provide factory-matched components and simpler installation, which can reduce installation errors and ensure proper airflow.
- Is stainless steel venting suitable for outdoor exposure?
Yes, especially for outdoor sections, stainless steel offers corrosion resistance and durability under temperature fluctuations.
- Should I hire a professional for vent installation?
For many residential setups, a licensed technician ensures code compliance, proper venting slope, and safe operation.