10 Best Direct Vent Condensing Water Heaters of 2026: Efficient, Space-Saving Picks for Reliable Hot Water

Choosing a direct vent condensing water heater is mostly about matching the right venting setup, fuel type, and capacity to your home. The best choice can improve efficiency, save space, and deliver consistent hot water.

Below, we focus on the most useful options for buyers who want dependable performance without overcomplicating installation or maintenance.

Best 10 Direct Vent Condensing Water Heater Picks for 2026

Direct Vent Condensing Pick – Norits NRC661 Tankless Water Heater, 120,000 BTU

If you want a direct vent condensing water heater for residential use, the Noritz NRC661 is built around continuous hot water delivery and efficient propane operation. Its 120,000 BTU output and tankless design make it a practical fit for homes that want strong performance without a bulky storage tank.

Best For: Homeowners using LP gas who want a wall-mounted tankless unit with condensing efficiency and direct vent flexibility.

Pros:

• 120,000 BTU output supports continuous hot water supply.
• Direct vent condensing design helps maximize heat extraction from exhaust gases.
• LP gas compatible and specifically designed for liquid propane operation.
• Wall-mount format and included vent kit support installation planning.

Cons:

• Designed for LP gas, so it is not a universal fuel choice.
• Max temperature is listed at 140 °F.
• Tankless systems typically require proper installation planning.

The NRC661 focuses on the core advantages buyers want from a direct vent condensing water heater: efficient heat use, compact wall mounting, and steady output for everyday residential demand.

Vent Kit Upgrade – Rheem ProTech RTG20320 Adjustable Concentric Vent Kit

For a direct vent condensing water heater installation, the Rheem ProTech RTG20320 is a stainless steel concentric vent kit made to manage fresh air intake and flue exhaust through an adjustable setup. It is useful when you need a cut-to-size vent solution that supports a clean concentric vent path.

Best For: Installers or homeowners who need an adjustable concentric vent kit for compatible direct vent water heater setups.

Pros:

• Adjustable concentric vent pipe can be cut to size.
• Pulls in fresh air and expels flue exhaust through one system.
• Stainless steel construction adds durability.
• Seal rings help prevent exhaust gas leaks at connection points.

Cons:

• It is a vent kit, not the water heater itself.
• Compatibility depends on the installation and venting needs.
• Designed for a specific venting application rather than universal use.

This is a practical add-on if your direct vent condensing water heater install calls for an adjustable concentric vent solution. The main value is in the flexible sizing and sealed exhaust management.

Outdoor Condensing Choice – Noritz NRC66ODLP Outdoor Tankless Water Heater

The Noritz NRC66ODLP is an outdoor condensing direct vent tankless water heater for liquid propane systems that emphasizes compact placement and very high efficiency. With a 6.6 GPM flow rate and low-NOx design, it is aimed at buyers who want endless hot water in a smaller footprint.

Best For: LP gas users who want an outdoor tankless unit with compact, high-efficiency operation.

Pros:

• Outdoor condensing design saves interior space.
• Very high efficiency with low-NOx operation.
• 6.6 GPM flow rate supports continuous hot water delivery.
• Includes a 12-year heat exchanger warranty and 5-year parts coverage.

Cons:

• Outdoor placement may not suit every home.
• Designed for liquid propane use.
• Maximum temperature is listed at 140 °F.

For shoppers comparing direct vent condensing water heater options, this model stands out for outdoor installation and space-saving design. It is a straightforward choice when efficiency and compact mounting matter most.

Termination Kit Choice – Rheem ProTech Concentric Direct Vent Termination Kit

When finishing a direct vent condensing water heater installation, the Rheem ProTech RTG20274A serves as a concentric horizontal termination kit for compatible systems. It is a direct replacement part for Rheem, Ruud, and Richmond water heaters and is intended for use with additional venting on walls up to 5 inches thick.

Best For: Owners or installers who need a genuine horizontal termination kit for compatible direct vent water heater setups.

Pros:

• Direct replacement part for Rheem, Ruud, and Richmond water heaters.
• Genuine factory-authorized OEM part.
• Designed for use on walls up to 5 inches thick.
• Includes hardware and instructions when applicable.

Cons:

• It is a termination kit, not a full heater.
• Requires additional venting to complete installation.
• Only suits compatible water heater systems.

This part is best viewed as an installation component rather than a standalone product. For the right compatible system, it helps complete the vent path needed for a direct vent condensing water heater setup.

Condensate Accessory – Rheem ProTech Condensate Tubing

If you’re shopping for a direct vent condensing water heater accessory, this Rheem ProTech condensate tubing kit is built for the drain line side of the job. It includes a 6-foot high-temperature silicone tube plus clamps, wire ties, and installation instructions, so it’s aimed at straightforward condensate routing where heat-resistant tubing is needed.

Best For: Replacing or installing condensate tubing on compatible tankless gas water heater setups.

Pros:

• Includes 6′ high-temperature silicone tube
• Comes with 2 clamps and 2 wire ties
• Installation instructions included
• Simple kit format for condensate routing

Cons:

• Not a venting kit for combustion exhaust
• Product details list a 0.5-inch outside diameter, so sizing should be checked carefully
• Specific appliance compatibility is not detailed in the notes

As a condensate-handling accessory, this kit is practical when you need the included hardware and a heat-tolerant tube in one package. It is not the vent itself, but it supports the drainage side of a direct vent condensing water heater install.

Horizontal Vent Kit – DiversiTech HVENT2 Vent Termination Kit

For a direct vent condensing water heater installation, the vent termination is a critical part of the system, and this DiversiTech HVENT2 kit is designed for high-efficiency fossil fuel appliances. It offers a low-profile horizontal vent solution that conceals intake and exhaust pipework, with all fittings included for a cleaner wall or roof termination.

Best For: Buyers who need a horizontal vent termination kit for high-efficiency tankless gas water heaters or similar appliances.

Pros:

• Designed to vent high-efficiency fossil fuel appliances
• Low-profile look conceals intake and exhaust pipework
• All fittings included for installation
• Can be used for horizontal or vertical installation per the notes

Cons:

• Specific appliance compatibility should be verified before purchase
• Vent sizing is fixed at 2-inch per the product name
• Installation still requires proper vent planning for the system

This is the most directly relevant option here if your goal is the vent termination portion of a direct vent condensing water heater setup. The clean, all-in-one design makes it easier to finish the exterior termination neatly while staying focused on high-efficiency venting.

Concentric Vent Pipe – Rheem ProTech 24" Stainless Straight Pipe

If you’re building out a direct vent condensing water heater vent run, this Rheem ProTech concentric straight pipe is made for venting tankless gas non-condensing water heaters and uses stainless steel construction. The 24-inch pipe features a one-step connection and a leak-proof seamless precision formed gasket, which makes it a straightforward choice for a clean vent section.

Best For: Extending or connecting vent sections on compatible tankless gas water heater installs.

Pros:

• Stainless steel construction
• 24 inches in total length
• One-step connection for fast installation
• Leak-proof seamless precision formed gasket

Cons:

• Listed for tankless gas non-condensing water heaters, not explicitly condensing models
• Only a single 24-inch pipe is included
• Compatibility should be checked against the vent system design

Among the three products, this is the vent-run component rather than a full kit, so it fits best when you already know the system layout. Its stainless build and gasketed connection are the main selling points for a tidy vent connection.

Direct-Vent Upgrade Pick – 36" Concentric Straight Vent Pipe for Rheem Tankless

If you’re comparing accessories for a direct vent condensing water heater setup, this 36-inch Rheem ProTech concentric straight vent pipe is built for quick replacement or new installation on compatible tankless gas systems. The stainless steel construction, 1-step connection system, and leak-proof gasket make it a practical option when you want straightforward venting with OEM fit.

Best For: Rheem tankless gas water heater owners who need a 36-inch concentric straight vent pipe with factory-authorized compatibility.

Pros:

• 1-step connection system supports fast, easy installation.
• Seamless precision-formed gasket is designed for leak-proof performance.
• Stainless steel construction adds durability.
• OEM genuine part for Rheem tankless gas water heaters.

Cons:

• Only works with compatible Rheem tankless systems.
• Length is fixed at 36 inches.

This is a strong fit if your project calls for a standard-length, stainless concentric vent component and you want the confidence of a factory-authorized replacement part.

Short-Run Venting Choice – 12" Concentric Straight Pipe for Non-Condensing Units

For a direct vent condensing water heater comparison, this 12-inch Rheem ProTech concentric straight pipe is a compact venting part made for tankless gas non-condensing water heaters. It focuses on simple installation, leak-resistant gasket design, and stainless steel construction, making it a straightforward fit when you only need a short vent section.

Best For: Owners of compatible tankless gas non-condensing water heaters who need a short 12-inch vent pipe.

Pros:

• 12-inch length works well for compact vent runs.
• 1-step connection helps simplify installation.
• Seamless precision-formed gasket is designed to be leak-proof.
• Stainless steel build supports durability.

Cons:

• Designed for non-condensing water heaters, not condensing models.
• Compatibility is limited to suitable tankless gas systems.

Choose this if your setup needs a shorter venting section and you specifically want a Rheem part for a non-condensing indoor tankless unit.

Compact Venting Option – 6" Stainless Concentric Pipe for Rheem

When you’re shopping for a direct vent condensing water heater accessory, this 6-inch Rheem ProTech concentric straight pipe is the shortest option in the lineup and is intended for Rheem branded tankless gas mid-efficiency indoor water heaters. It keeps the setup simple with a 1-step connection and leak-proof seamless gasket, while the stainless steel construction supports everyday durability.

Best For: Rheem branded tankless gas mid-efficiency indoor water heaters that need a compact 6-inch vent section.

Pros:

• Very short 6-inch length for compact venting needs.
• 1-step connection makes installation easier.
• Leak-proof seamless precision-formed gasket.
• Stainless steel construction for durability.

Cons:

• Only suitable for compatible Rheem branded units.
• Short length may not fit larger venting layouts.

This is a practical pick if you need a compact concentric vent component and want an OEM-style part designed specifically for eligible Rheem tankless systems.

How We Picked the Best Direct Vent Condensing Water Heater Options

We prioritized models and venting components that support efficient operation, proper exhaust handling, and practical installation. For a Direct Vent Condensing Water Heater, compatibility matters as much as output, so we looked at venting style, gas type, capacity, and the kinds of homes these products fit best.

Quick Comparison

Tankless units in this roundup are best for homeowners who want compact, on-demand hot water and high efficiency. The venting parts are best for buyers replacing or extending an existing system, or for installers who need the correct concentric pipes, termination kits, and accessories to complete the job.

Key Buying Factors for a Direct Vent Condensing Water Heater

Venting Type and Compatibility

Confirm whether your system uses concentric venting, horizontal termination, or outdoor installation. A Direct Vent Condensing Water Heater depends on the correct vent path for safe combustion air intake and exhaust removal, so matching the manufacturer’s specifications is essential.

Fuel Type and Capacity

Check whether the unit is propane or natural gas compatible, then size it for your household demand. Flow rate, BTU rating, and climate all affect how well a unit can keep up with showers, laundry, and simultaneous use.

Installation Space and Wall Thickness

Measure clearances carefully. Some termination kits and vent pipes are designed for specific wall thickness ranges, and the wrong length can create unnecessary installation complications.

Condensate Management

Condensing systems create acidic condensate that must be drained properly. Make sure the installation includes the right tubing or drain setup to protect the appliance and surrounding materials.

Who Should Buy Which Direct Vent Condensing Water Heater?

If you want a full hot water solution, choose a tankless Direct Vent Condensing Water Heater with the right output for your household. If you already own a compatible unit, the venting kits and straight pipe sections in this roundup are better for replacements, extensions, or code-compliant installation updates. Homeowners working with an existing Rheem or Noritz system should pay close attention to brand-specific part numbers to avoid fit issues.

In short, buy for compatibility first, then compare efficiency, vent length, and installation needs. That approach will help you choose the right setup the first time.