Best Direct Vent Water Heater – (Reviews & Buying Guide 2020)

Is your home currently under renovation? Did you recently buy a new home and are having some reconstruction done? The plumbing and water heating are two of the main aspects of any house remodeling and should be researched well. This article talks about direct vent water heaters.

Finding the best direct vent water heater can take some time. That’s why we, at Beyond Shower, hope we can help. We have also prepared six direct vent water heater reviews and a buying guide with essential information about such units.

Direct vent water heaters are something you should take into consideration when renewing your water heating system and bathroom. They are suitable for houses with or without chimneys. Direct venting means that the heater gets its air from outside and releases the exhaust hot fumes outside. This happens through the roof or an exterior wall. Thus, these units reduce the chances of accidental fires.

Best Direct Vent Water Heater Comparison Chart

Takagi T-H3M-DV-N Condensing Direct Vent Tankless Water Heater

Takagi T-H3M-DV-N Condensing Direct Vent Tankless Water Heater

  • Price: $$
  • Dimensions: 17.8 x 13.1 x 29.5”
  • Flow Rate: 6.6 GPM
  • Weight: 49 pounds
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Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater

Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater

  • Price: $$$
  • Dimensions: 6.7 x 13.8 x 23.6”
  • Flow Rate: 6.5 GPM
  • Weight: 39 pounds
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Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

  • Price: $$$
  • Dimensions: 6.7 x 13.8 x 20.3”
  • Flow Rate: 6.6 GPM
  • Weight: 38 pounds
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Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater

Rheem RTGH-95DVLN Direct Vent Tankless Natural Gas Water Heater

  • Price: $$$$$
  • Dimensions: 18.5 x 9.8 x 27.5”
  • Flow Rate: 9.5 GPM
  • Weight: 79 pounds
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Rheem RTGH-84DVLN Indoor Direct Vent Natural Gas Condensing Tankless Water Heater Low Nox

Rheem RTGH-84DVLN Direct Vent Natural Gas Condensing Tankless Water Heater

  • Price: $$$$
  • Dimensions: 9.8 x 18.5 x 27.5”
  • Flow Rate: 8.4 GPM
  • Weight: 77.9 pounds
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EZ Deluxe Tankless Water Heater

EZ Deluxe Tankless Water Heater

  • Price: $
  • Dimensions: 6 x 16 x 24”
  • Flow Rate: 3.4 GPM
  • Weight: 31 pounds
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Best Direct Vent Water Heater – (Editors’ Choice)

We’ve listed the six reviewed products in no particular order.

1. Takagi T-H3M-DV-N Condensing Direct Vent Tankless Water Heater

Takagi T-H3M-DV-N Condensing Direct Vent Tankless Water HeaterThe Takagi T-H3M-DV-N is a condensing indoor tankless water heater made in Japan that must not and cannot be installed outdoors. There’s a separate outdoor unit that you can purchase if you need outdoor installation.

The unit is a condensing natural gas tankless heater and has an intake vent and vent for exhaust. With a little bit of imagination, you can use only the combustion vent and get air from inside of the room. To do that, the heater needs to be in a well-ventilated room


  • The unit has an overheat cut off fuse and an internal freeze protection system.
  • This heater has an exhaust and water temperature safety control feature.
  • The product’s noise level is very low, as it is a sealed combustion unit.
  • You may use this unit for floor heating and nothing else. For faucets and appliances, you will need another heater.


  • The inlet filter of the heater is quite small and can quickly get clogged. You may need a pre-filter to protect it.
  • The warranty is strict and requires professional installation in order to cover repairs.

2. Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater

Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater uses natural gas to heat your water. The same model is available with propane too. If you get one type, it can’t be converted to use the power source of the other. An advantage of this heater is that both the exhaust and intake vent pipes can be PVC, making them easy to set up.

The heater comes with pre-set factory settings that are suitable for multiple uses. You can run several appliances that use hot water at the same time. The unit can produce 6.6 gallons of hot water a minute which is enough for two showers to work without temperature change.

You can use a recirculating pump with this unit which will deliver hot water to any faucet in the house as soon as you turn it on. This unit allows for ventilation through the roof if there’s no exterior wall available to use for the purpose.


  • Based on rough calculations, the heater can lower your gas consumption (and bill) by 10%-20%.
  • The unit has a timer that you can use to set a recirculating pump.
  • This product has a 12-year warranty on the heat exchanger and a 5-year for the parts.
  • This heater can be used for households at 6,000 feet above sea level.


  • High costs for installation, spare parts, and repair.
  • This unit cannot be used for floor heating.
  • This heater doesn’t work with propane.

3. Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

Takagi T-KJr2-IN-LP Indoor Tankless Water HeaterThis Takagi T-KJr2-IN-LP Indoor Tankless Water Heater comes with a built-in exhaust fan and convenient remote control. It has some useful features, including anti-freeze and overheat protection. Additional features are surge protection and troubleshooting diagnostic codes. This water heater also has a flow sensor and won’t ignite unless there’s a minimal flow passing through it.

This unit has a maximum of 6.6 GPM flow rate and a temperature range from 122F to 167F. Perfect for most households, but not suitable for houses at more than 10,000ft above sea level. Luckily, most houses are far below the maximum altitude.

The venting kit may be a bit hard to find or must be ordered separately. The unit should be flushed with vinegar at least once a year for homes with hard water to prolong its life and keep the good performance. With an additional pump, the heater can be used for well water.


  • This unit comes with a remote control to adjust temperature instead of the old version’s dip switches.
  • The heater’s display shows the current GPM and water temperature.
  • Not loud at all. If it’s installed in a basement or an attic, you won’t hear it.
  • The anti-freeze protection works for temperatures down to 5 degrees.


  • To get a full warranty, the unit must be installed by a professional plumber.
  • The exhaust gets too hot and it must-have stainless steel venting.

4. Rheem RTGH-95DVLN Direct Vent Tankless Natural Gas Water Heater

Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water HeaterRheem is a well-known brand in the world of water heaters and coolers. Their direct vent tankless water heater is advertised as being 94% energy efficient. This brand’s house water heaters are not suitable for hydronic floor heating since the units provide hot water on demand.

Hydronic floor heating requires constant hot water flow, which this model isn’t built to endure. Therefore, the unit won’t be covered by the warranty if that’s what you use it for.

A lot of additional parts are required like exhaust pipe and gas pipe fittings, for the installation of the product. Plus, if you want to use the unit’s warranty, you have to pay a professional plumber to install it.

Because of the fan that turns on to push out the exhaust fumes, this water heater is nosier than others. You’d want to be careful where you place it because you will hear it when it runs.

The water should be flushed regularly, and regular cleaning of the unit is a must for homes with hard water.


  • 2-degree increments in temperature change.
  • It works with low water flow.
  • You can use multiple appliances or take two showers at the same time.
  • 12 years warranty for the heat exchanger.


  • Noisier than other units.

5. Rheem RTGH-84DVLN Direct Vent Natural Gas Condensing Tankless Water Heater

Rheem RTGH-84DVLN Indoor Direct Vent Natural Gas Condensing Tankless Water Heater Low NoxThe Rheem RTGH-84DVLN is a condensing tankless water heater that reaches temperatures from 120 degrees to 140 degrees. This unit works only with natural gas. It cannot be converted to using propane. If your home has a propane supply, you can order this model’s propane version.

This unit’s installation requires a bit of planning ahead of time. You will need to check the manual and go to the store to buy the tools and pipes you’ll need with one trip. The package consists of the heater, a gas shut-off valve, and a pressure relief valve. The good thing about it is that installing it yourself won’t void the warranty.

The electrical requirements for this heater for normal operation are 100W. However, the antifreeze protection needs 200W to work.  With this unit, you can use PVC pipes for both the intake and exhaust. PVC is the more convenient and flexible option to work with, plus such pipes are more affordable.


  • Punctual and helpful technical support from Rheem.
  • The product has Energy Star Certification. It is given to products that are energy-efficient and environmentally-friendly.
  • This water heater has anti-freeze protection, which works down to 30 degrees.
  • This product has a Low NOx ignition which means it emits less harmful gases than other heaters.
  • The unit works with .40 flow rate for activation and then can work even with .26.


  • Makes a loud, humming noise when it’s being used.

6. EZ Deluxe Tankless Water Heater

EZ Deluxe Tankless Water HeaterThe EZ Deluxe Tankless Water Heater a great indoor water heater option for homes at high altitudes. The unit’s propane regulator can be adjusted to work at the appropriate altitude. Keep in mind that if you live at or above 4000 ft you should get a heater with higher GPM to compensate for the low flow.

This new and improved version of the unit is suitable for homes with up to two bathrooms. Furthermore, two showers can be used simultaneously without a negative effect on water flow or temperature.

This unit is also suitable for houses with low pressure, but it needs at least 35 PSI. Another advantage of this heater is that it has an advanced intelligent design. This means that if the power is out or you restart it, it will remember the last setting.

The unit has a sensor stabilizer that senses pressure changes. It stabilizes the exit water flow, so no problems occur to appliances and pipes, and to you when showering. Additionally, it has another protection for water supply cut-off. When the heater senses that the water flow is interrupted, the gas valve shuts off automatically.

This heater requires electricity to work so you won’t be able to use it off-grid. You can install it in a basement or a garage. However, if the temperature in the garage gets very low in the winter, you will need to insulate the heater because it doesn’t have protection.


  • This heater’s ignition works with low water flow, making it suitable for more households.
  • This unit has a fully automatic operation of the gas supply and exhaust fan.
  • The heater’s size is 6x16x24 inches – compact and lightweight.
  • This product has a flow stabilizer that controls the exit water flow regardless of any changes that may occur.


  • It doesn’t have freeze protection.
  • It does not have a wall thimble included in the package.

What is a Direct Vent Water Heater?

Direct Vent Water Heater ReviewsIf a water heater is a direct vent model, this means that a vent pipe is going through an exterior wall or the roof to get its air from outside. The exhaust gases are also vented outside through another vent pipe (usually a double-wall vent duct is required).

Why is this type of venting better? Because it reduces the chance of accidental fire, and there’s no backdraft affecting the gases. All of the hot air and vapor are vented outdoors and not inside of your property. This type of venting is recommended for houses without chimneys.

If this doesn’t work for you or in case you think you will be interested in other water heating options, check out our articles on various shower and water heating systems and accessories. We at Beyond Shower always strive to deliver up to date content on the top products in this category.

What is Backdrafting?

Hot air is lighter than cold air, and the vent pipe of the water heater exudes hot air. Sometimes as the hot air passes through the vent pipe, the air pressure indoor becomes low. This sucks back the harmful gases into the house, this is the process called back-drafting.

How Does a Direct Vent Water Heater Work?

This type of water heaters uses propane or natural gas to heat water. Since it uses gas, it needs an air intake in order for combustion to take place. Thus, the exhaust gasses are also carried outside of the house. Without proper ventilation, the combustion gases would enter your house and cause health problems.

The vent pipe for a DV heater consists of a large and a small pipe within the large one. The small one exhausts the hot gasses, and the large one is for the fresh air intake.

All you need to set this system up is an exterior wall for the exhaust pipe to pass through. No roof access or chimney is required. If the attic is the place where the system will be installed, it’s okay.

Direct vent water heaters can use either a small pipe within a large pipe for the intake and exhaust process. The two separate pipes can be used as well, depending on the water heater model.

Types of Water Heater Ventilation

If you’ve settled on buying a direct vent tankless water heater, you should take the ventilation system into account. Different types suit different house layouts.

  • Atmospheric venting is the process where exhaust gasses rise out of the combustion chamber of the heater. The gas naturally rises through a chimney-like pipe that exits from the roof.
  • Direct venting is the type this buying guide is about. It is the process where the exhaust goes through a pipe on an exterior wall. It also takes its air from outside through another pipe.
  • Power venting uses a fan to pass the exhaust through the vent pipe. This type of venting doesn’t require access to the roof as well. It works with an exterior wall. It also takes air from inside of the hose to work.

Direct Vent vs. Power Vent

Best Direct Vent Water HeaterThe ‘better one’ is the one type that suits your situation. Both are efficient, and it depends on how your home is laid out. Both models have their advantages and drawbacks. Here is a little bit more about direct venting vs. power venting:

  • Location: Power vents have more extended flues and can reach up to 40 feet. They need to be in a well-ventilated room with good airflow. On the other hand, direct vents need to be close to a chimney, if they will use it for expelling the hot gases. As a general rule of thumb, direct vents should be four feet away from an adjoining wall, and any other appliance. The unit needs space so it can use a natural airflow.
  • Efficiency: Power vent heaters require more electricity to function so your energy bill may spike. They are the more advanced option of the two. Additionally, they offer more flexibility with the installation as they can be installed through an exterior wall. Such units don’t require a chimney-like most direct vents do.
  • Noise: The direct vents make almost no noise at all. You can barely hear them while they work even if you’re next to one. On the other hand, power vents can make a noise while working.
  • Costs: The direct vent is the more affordable option. With power vents, you should add the cost for fans and pipes, among others. Also, power vents require more electricity to work, and that is reflected in your monthly bill as well.

Can I Replace a Power Vent Water Heater with a Direct Vent?

The short answer is Yes. You can. But not always, and not in every home. As they require a different house layout, not every type of direct vent heater will work as a replacement of a power vent unit. If you decide to switch one for the other, some modifications will be necessary. This process will take up time, money, and you’ll need a real expert plumber to do it.

If you don’t have the money or time to wait, you wouldn’t want to try replacing a powerful heater with a direct vent unit. If you’re in such a situation, you can read our guide on whole house electric tankless water heaters for additional information on power heating systems. Thus you can choose another type of unit to replace your existing one.

Installation of Direct Vent Water Heater

The installation of a direct vent water heater isn’t the hardest thing in the world. However, keep in mind that some manufacturers require professional installation or the warranty will be void.

That being said, if you’re in the know about plumbing and water heaters, you shouldn’t have a problem.

Most units have stainless steel pipes for the hot gasses to pass through without damaging the pipe. Some of the more expensive units can use PVC or ABS pipes. They are even easier to work with and more affordable.

The installation of a direct vent water heater depends on your house’s layout. Since it doesn’t require to be connected to a chimney, it should fit most house types.

Furthermore, this type of water heater can also be used for outdoor showers. For more information, you should check our reviews on outdoor solar showers.

The pipes can be installed vertically or horizontally, depending on the model or your home.

  • Vertical pipes installation allows the exhaust gases to move easily and get out naturally and more quickly.
  • Horizontal pipes installation should have as few turns and curves as possible. The combustion chamber helps the exhaust gases move up quickly and help the air intake. It is more convenient for smaller spaces.

With direct vent systems, there’s nothing forcing the exhaust gasses out. This means that the pipes should be clear to provide a straightforward and unobstructed pass.

FAQ About Direct Vent Water Heaters

Here are some of the questions that frequently pop up while researching direct vent water heaters, or any other product.

Q: How should I maintain my tankless water heater?

A: You should at least once a year flush the water out and flush the heater with vinegar. Regardless of whether your water is hard or not.

Q: What tools do I need for the installation?

A: Some of the tools you’ll need are: caulk gun, drill, adjustable wrench, and screwdriver. Plus, the direct venting kit, of course.

Q: Must the vent pipe be stainless steel?

A: Not if the unit is condensing. Such units are more efficient and do not have temperatures as high as non-condensing models. This allows for the use of PVC or ABS pipes.

Q: Why is my hot water pipe dripping?

A: Possible reasons for this problem are: improper installation, damaged pipe, the pipe is old. If you’re not a plumber yourself, call a professional to inspect and replace it.

Q: How do I know how big of a tankless water heater I need?

A: Tankless water heaters provide hot water on demand. You use as much hot water as you need. You should check products’ descriptions of how many faucets or appliances can be used at the same time. Then buy a unit that fits your household’s needs or a little bit bigger, just to be sure.

Other heater types we have reviewed are outdoor tankless water heaters and whole-house electric tankless water heaters.

Safety Tips

Regardless if you or a professional is installing the water heater, safety measures should be taken. For starters, you should choose the right size water heater for your home. A too big or too small system can pose a safety hazard.

Additional safety tips:

  • Keep flammable items and materials at least one foot away from the heater. Also, if the unit takes its air from inside the room, there shouldn’t be anything near it at all.
  • Make sure kids do not have access to the water heater.
  • Test the relief valves if any. If you’re not a licensed plumber, you should hire a technician. Test if the heater behaves properly in case of over-pressurizing or high temperatures.
  • If you live in an area with frequent earthquakes, you can get straps for the heater. This is an essential precautious measure for heaters that use any type of fuel. Strapping the unit will keep the unit and its gas connections safe during an earthquake.
  • Make sure the vent pipes are the right size and aren’t clogged.
  • Invest in a gas shut-off valve to protect the unit if the gas flow increases drastically.
  • Keep the system above the ground to prevent the ignition of leaked gas or vapors.
  • To comply with EPA’s safety recommendations, the water temperature is set to 120F by default on most models. You may turn it up for a hot shower and bring it back to 120F.

Wrap up

Switching from a water storage water heater to a tankless one will prove to be an excellent option for many households. It is important to choose a good brand, quality materials, and the right size for your house.

That being said, there are other things to consider before purchasing a system. One of the main things is to choose the right venting system. Hopefully, our direct vent water heater reviews and our buying guide will provide you with enough objective information to make the right decision.

Choosing the best direct vent water heater will prove to be a great investment for your house. With such a system, you can have hot water in demand at any time without having to wait to re-heat. You will be able to run two showers simultaneously or run several appliances that work with hot water without any problems.

You can find more reviews on our homepage including the best acrylic bathtubs and top-notch Bluetooth speakers for showers.