Eccotemp 3" Stainless Steel Horizontal Vent Kit with 2.5 in Adapter - 1779686052177_313

Eccotemp 3" Stainless Steel Horizontal Vent Kit with 2.5 in Adapter - 1779686052177_313

3" Single walled Horizontal Stainless Steel Vent Kit with 2.5" to 3" Paloma Adapter for i12 and FVi12 Series Tankless Water Heaters. You may need to purchase additional Eccotemp straight pipe.

Includes 

• (1) 3" x 12" Straight Pipe
• (1) 3" x 90 Degree Elbow
• (1) 3" Adjustable Wall Thimble
• (1) 3” x 6" Universal Adapter
• (1) 3" Termination Hood w/Damper
• (1) 2.5" to 3" Paloma Adapter

What our Experts Think 

• A purpose-built 3" stainless steel horizontal vent kit with 2.5" adapter, designed for safe and code-compliant venting of compatible Eccotemp tankless water heaters.
• Made from AL-294C stainless steel, offering strong resistance to corrosion and high exhaust temperatures for long-term durability in outdoor wall exhaust applications.
• Includes a complete venting setup: straight pipe, 90° elbow, wall thimble, termination hood with damper, and 2.5"→3" adapter, ensuring a full horizontal installation solution out of the box.
• Designed specifically for horizontal side-wall venting, helping safely expel combustion gases from indoor tankless systems while maintaining proper airflow efficiency.
• We like the modular pipe sizing options (multiple straight pipe lengths available), allowing installers to customize vent runs based on wall thickness and building layout.
• Engineered for Category II/III venting systems, supporting high-efficiency gas appliances with strict safety and pressure requirements.
• Compatible with select Eccotemp tankless lines (including SHLX and similar series), making it a brand-matched, low-risk installation component.
• Best suited for professional installation or experienced DIY users, since correct vent length, slope, and termination spacing are critical for safe operation.

Q&A    

Q: What is the Eccotemp 3" Stainless Steel Horizontal Vent Kit with 2.5" Adapter?
A: It is a stainless steel venting system designed for indoor tankless water heaters, allowing safe horizontal exhaust of combustion gases through an exterior wall while ensuring proper airflow and compliance with safety standards.

Q: What is included in this vent kit?
A: The kit typically includes a 3" straight pipe, 90° elbow, adjustable wall thimble, universal adapter, termination hood with damper, and a 2.5" to 3" stainless steel adapter for compatible SHLX and related series heaters.

Q: Which water heaters is it compatible with?
A: It is designed for Eccotemp models such as SHLX Series, 20HI Series, SH12-A Series, 6GB Builder Series, and 6.5GB Builder Series, ensuring proper vent sizing and safe exhaust performance.

Q: Why is a 2.5" to 3" adapter included?
A: The adapter is used to convert smaller 2.5-inch heater exhaust outlets to a standard 3-inch vent system, improving airflow stability and ensuring correct vent matching for installation safety.

Q: What material is the vent kit made from?
A: It is constructed from AL-294C stainless steel, designed to resist corrosion and withstand high-temperature exhaust gases in Category II/III venting applications.

Q: Is this suitable for outdoor use?
A: No. This is strictly for indoor tankless water heater installations, where exhaust must be vented horizontally through a wall termination point.

Q: What is the maximum vent length?
A: The system typically supports a maximum vent run of about 20 feet, with reductions for each 90° elbow to maintain safe exhaust flow.

               
Maintenance Tips

• Ensure proper 3" horizontal vent slope (slight upward pitch) to prevent condensate buildup and backflow issues.
• Inspect and tighten all joints, wall thimble, and termination hood periodically to maintain a fully sealed exhaust path.
• Check the 2.5" → 3" adapter connection regularly for secure fitment and no air leakage at the transition point.
• Clean exterior termination hood every few months to remove dust, soot, or insect blockages that can restrict airflow.
• Verify vent run does not exceed manufacturer limits (typically ~20 ft minus elbow reductions) to ensure safe combustion and efficiency.
• Inspect stainless steel pipe sections for corrosion, dents, or heat discoloration, especially after heavy use or weather exposure.
• Ensure wall penetration and thimble remain weather-sealed to prevent moisture ingress into the structure.
• During servicing, confirm no condensation pooling inside pipes, especially in long horizontal runs.
• Keep vent path clear of obstructions (plants, debris, or stored items) outside the termination area.
• If unusual error codes or flame instability occur, check venting first for blockage or disconnection issues.