Direct answer: For on‑demand (tankless) water heater venting, choose vent components and termination kits that fit standard 2.36″ diameters, stainless steel construction, and proven safety features. The top picks below suit homeowners installing gas or combo venting in residential spaces, with options for both wood stove partnerships and dedicated vent terminations. Each product is selected for durability, compatibility, and clear installation guidance. The buyer persona most served includes DIY installers, small homes, and remodel projects seeking reliable, corrosion‑resistant venting components.
Summary of chosen products
| Product | Best For | Why It Stands Out | Includes |
|---|---|---|---|
| Vent Kit for Tankless Water Heater and Wood Stove | Gas water heaters and wood stoves | Premium 304 stainless, corrosion resistant, easy install | Vent pipe, fittings |
| Rheem RTG20280-1 Tankless Horizontal Vent Termination Kit | Standard vent runs | Durable stainless steel, complete wall plate, 94° elbow | Wall plate, screws, elbow |
| APUS Propane Tankless Water Heater | Compact homes needing indoor venting flexibility | LED, precise temp control, energy‑savvy design | Indoor venting features, control interface |
| MIZUDO Natural Gas Tankless Water Heater | Whole‑home hot water with high flow | High GPM, precise control, anti‑freeze | WiFi & App control, CSA Certified |
| Stiebel Eltron Tempra 29 Plus Electric Tankless | Electric tankless with no venting required | On‑demand hot water, space‑saving, multi‑preset | Two temperature presets, hard‑wired install |
Vent Kit for Tankless Water Heater and Wood Stove
Best for: Homeowners venting a combination of a tankless water heater and a wood stove where standard 2.36″ diameter vent piping is needed. This kit uses premium 304 stainless steel for corrosion resistance and long‑term durability. It is ideal for installations that demand secure containment of exhaust gases and smoke, with straightforward assembly. The kit is best for DIYers seeking an all‑in‑one venting solution that aligns with common sizing requirements.
Why selected: Durability and compatibility with common vent sizing make this kit a versatile choice for safer exhaust and efficient venting. Stainless steel construction supports high‑temperature exhaust and reduces backdraft risks.
Caution: Verify your exact vent length requirements; the kit’s fixed length may require additional adapters or additional piping for longer runs.
Rheem RTG20280-1 Tankless Horizontal Vent Termination Kit
Best for: Installers seeking a complete horizontal termination solution for tankless units with a reliable wall plate and elbow fittings. This kit is suited for standard exterior vent terminations where space and layout require precise alignment.
Why selected: It offers durable stainless steel components, a 12″ wall plate, and a 94‑degree elbow to simplify vent routing and secure mounting. This combination supports tidy, code‑friendly installations and reduced air leakage risk.
Caution: Ensure compatibility with your specific tankless model and local venting codes when selecting termination components.
APUS Propane Tankless Water Heater
Best for: Small homes or apartments needing reliable on‑demand hot water with compact indoor design and smart temperature control. APUS’s unit targets spaces with limited venting options while offering user‑friendly features.
Why selected: The unit provides precise temperature control with an LED display, stable performance, and energy efficiency through smart regulation. The compact footprint enables flexible installation in tight interiors.
Caution: If you require very high output for multiple fixtures simultaneously, verify that 80,000 BTU and 3.6 GPM meet your peak needs.
MIZUDO Natural Gas Tankless Water Heater
Best for: Whole‑home hot water with high flow demands across multiple bathrooms and appliances. This model is ideal for larger households needing consistent on‑demand performance and smart control capabilities.
Why selected: With up to 10.3 GPM and 199,000 BTU, it supports simultaneous hot water use and maintains stable temperatures with precise control. The app control adds convenience for monitoring and adjusting settings remotely.
Caution: Larger homes may need professional sizing to ensure adequate venting and gas supply; verify venting route and clearances per local codes.
Stiebel Eltron Tempra 29 Plus Electric Tankless
Best for: Electric systems or homes without venting requirements. The Tempra 29 Plus is ideal for users who prefer electric tankless operation and space efficiency in ventless setups.
Why selected: It provides on‑demand hot water with a compact, sleek design and dual temperature memory presets. This unit is notable for its space saving and energy management potential in all‑electric homes.
Caution: It requires a hard‑wired 240/208‑volt service and may demand substantial electrical capacity; confirm electrical availability before purchase.
Buying Guide: Key Considerations for On‑Demand Water Heater Venting
- Vent sizing and compatibility: Confirm the vent diameter (common sizes include 2.36 inches in these products) and ensure fittings match your water heater model.
- Material durability: Stainless steel vent components resist corrosion and high temperatures, reducing maintenance needs and safety risks.
- Installation type: Determine whether your system requires horizontal vent termination, wall plates, elbows, or a compact indoor vent routing solution.
- Vent safety and code compliance: Verify that venting installs meet local building codes and manufacturer guidelines to prevent backdraft and gas buildup.
- System type: Gas, propane, and electric tankless units have different venting needs. Electric models often do not require venting, while gas/propane units do.
- Output needs: Size the unit by peak simultaneous usage (GPM) to ensure continuous hot water without temperature swings.
- Smart controls and diagnostics: Apps and LED displays help monitor temperature stability and performance for on‑demand systems.
Frequently Asked Questions
- Do all on‑demand water heaters require venting?
- What is the common vent diameter for these kits?
- Is stainless steel essential for vent components?
- What should I check before buying a vent termination kit?
- Can I mix units from different brands?
- How do I know if I need a horizontal or vertical vent termination?
Gas and propane tankless units require venting to exhaust combustion gases, while electric models do not require venting.
Several kits use a 2.36 inch diameter vent pipe, which fits many standard installations.
Stainless steel is preferred for durability, corrosion resistance, and safe high‑temperature venting.
Confirm compatibility with your heater model, confirm local code compliance, and ensure the kit includes all required fittings and wall plates.
Mixing brands may lead to non‑compliant installations; use components specified for your heater model or consult a professional.
Horizontal terminations are common for exterior walls, while vertical terminations are used when venting through a roof or higher structure; follow manufacturer guidelines.