The best tankless water heater exhaust part is the one that matches the heater’s approved venting system, pipe diameter, and installation layout. The Rheem termination kit and concentric vent pipe are options to consider for compatible Rheem systems; DiversiTech’s low-profile kit is designed for 2-inch horizontal venting, while Blulu and VATTCEEL offer stainless-steel pipe components. Confirm the appliance manual’s requirements before buying: a part’s listed dimensions alone do not establish compatibility.
| Product | Best suited for | Listed feature |
|---|---|---|
| Rheem RTG20280-1 Termination Kit | Compatible Rheem horizontal installations | Wall plate and angled elbow |
| Rheem RTG20270A Concentric Vent Pipe | Compatible Rheem vent setups | One-step connection and gasket |
| DiversiTech HVENT2 Kit | 2-inch horizontal vent applications | Low-profile appearance |
| Blulu Direct Vent Pipe Kit | Setups calling for listed 3-inch components | Elbow and termination pipe |
| VATTCEEL Vent Pipe | Applications that specifically accept its dimensions | 304 stainless steel pipe |
Rheem RTG20280-1 Horizontal Termination Kit
This kit is best for buyers whose Rheem tankless water heater instructions specify this termination style. It includes stainless-steel components, a 12-inch wall plate with mounting screws, and a 94-degree elbow. Those included parts make it a focused option for a horizontal wall termination rather than a general-purpose length of vent pipe.
Why it was selected: The product is specifically identified as a tankless horizontal vent termination kit and provides several components for that configuration. Limitation: The listing does not provide a full compatibility list or pipe diameter. Check the heater documentation and installation requirements before ordering.
Rheem RTG20270A Concentric Vent Pipe
Choose this 6-inch concentric vent pipe if the appliance’s approved venting plan calls for the RTG20270A component. The listing describes stainless-steel construction, a one-step connection, and a seamless precision-formed gasket intended to provide a leak-resistant connection.
Best for: Buyers seeking a specified Rheem vent component with a connection-focused design. Why it was selected: Its product name identifies it as a tankless concentric vent pipe, making it directly relevant to exhaust-system replacement or installation planning. Limitation: The listing does not state its length or provide a complete appliance compatibility chart, so verify both details before purchase.
DiversiTech HVENT2 Horizontal Vent Kit
The DiversiTech HVENT2 is best for a compatible installation that calls for a 2-inch horizontal termination. The listing describes it for high-efficiency fossil-fuel appliances, including tankless water heaters and furnaces. Its low-profile design is intended to conceal intake and exhaust pipework for a tidier exterior appearance.
Why it was selected: It combines a stated 2-inch size with horizontal termination and a concealed-pipework design. Limitation: The description references multiple appliance types but does not establish that it fits every tankless model. Confirm the heater’s venting instructions, including whether a separate intake and exhaust arrangement is required.
Blulu Stainless Steel Direct Vent Pipe Kit
This kit is best for buyers whose approved setup calls for a 3-inch outside-diameter elbow and a 3-inch outside-diameter, 19.7-inch horizontal termination pipe. The listed package includes one vent pipe and one elbow. The termination pipe is described as 201 stainless steel, selected for heat resistance and wear resistance.
Why it was selected: It supplies two named vent components and gives specific dimensions to compare with an installation plan. Limitation: The product description emphasizes checking the diameter. Do not assume it suits a particular water heater just because the dimensions appear close; confirm the exact vent type and material requirements.
VATTCEEL Stainless Steel Vent Pipe
This pipe is best for an application that explicitly accepts the listed 2.36-inch diameter and 14.56-inch length. The seller describes 304 stainless steel construction and use with gas water heaters and wood-burning stoves. It is presented as a single pipe, not as a complete termination assembly.
Why it was selected: Its stated exhaust use and corrosion-resistant steel make it relevant to buyers comparing individual vent components. Limitation: The listing does not identify a specific tankless heater model or provide enough information to confirm a complete vent system. Verify dimensions and appliance approval before use.
Buying Guide: How To Choose Tankless Water Heater Exhaust Parts
Which vent size and configuration does the heater require?
Start with the water heater’s installation manual and model number. Check required vent diameter, vent type, material, maximum run, termination style, and whether the system uses separate intake and exhaust pipes or a concentric arrangement. A product’s diameter or general “tankless” description is not a substitute for appliance-specific approval.
Do you need a pipe, elbow, or termination kit?
A pipe extends a vent run, an elbow changes direction, and a termination kit helps form the exterior end of a horizontal vent. Some listings include multiple pieces; others describe a single component. Compare the package contents with the parts your installation actually requires so you do not mistake a pipe for a complete vent system.
What should you check about materials and installation?
Match the material and connection method to the heater manufacturer’s instructions. Stainless-steel construction appears in several listings, but steel grade and dimensions differ. Check whether the kit includes a wall plate, gasket, fasteners, elbow, or termination cap as needed. Exhaust work affects combustion-gas removal, so use a qualified installer when required by local rules or when the installation is uncertain.
Frequently Asked Questions
Can any stainless-steel pipe vent a tankless water heater?
No. The pipe must meet the appliance manufacturer’s venting requirements for size, material, configuration, and installation. Stainless steel alone does not confirm compatibility.
Is a horizontal termination kit the same as a complete vent system?
Not necessarily. A termination kit may cover only the exterior termination and related components. Check the listed contents and the heater’s venting plan.
What does concentric venting mean?
A concentric vent uses a combined arrangement for intake air and exhaust. Confirm that the specific water heater is designed for the listed concentric component before selecting one.
Should I choose a 2-inch or 3-inch vent part?
Use the diameter required by the heater’s approved venting instructions. Do not choose based only on the product name or a measurement that seems close.
Can I install tankless water heater exhaust parts myself?
Installation rules vary by appliance and location. Follow the manufacturer’s instructions and local codes, and consult a qualified professional if you cannot verify the venting requirements.