Why Are Direct Vent Water Heaters So Expensive?

One of the key considerations when buying a gas water heater is the venting system. Unlike electric water heaters, all gas hot water heaters require a venting system to eliminate the exhaust gas produced during the combustion process. There are two most common types of venting systems: direct vents and power vents.

Contrary to the common assumption, direct vent water heaters are cheaper to install and operate than power vent water heaters. A direct vent is easy to install at minimal cost as you only need a vertical vent pipe. On the other hand, a power vent requires to be connected to a dedicated electric source to power the blower motor.

This article will discuss in detail the operational mechanism, pros, and cons of each type of venting system and answer the top power vent vs. direct venting FAQs.

What is Better: Power Vent or Direct Vent?

Both venting systems work well for different propane and natural gas waters heaters regardless of whether it is a tankless unit or storage tank water heater. However, each venting system has a specific design and operational mechanism which presents pros and cons. Below is a detailed comparison of the two types of venting systems and their pros and cons.

Direct vent water heaters are simpler and cheaper to install. Usually, a vertical vent is placed against a wall with the flue gas pipe running through a single opening that terminates at the roof. Direct venting systems work well whether there is electricity or not.

Power vent water heaters have more moving parts, which makes them more complex and costlier to install. They can use either a vertical or horizontal vent pipe as the blower or fan provides the momentum to move the exhaust gases. You require an electrician or a water heater specialist to set up the powerlines for the fan. Since the venting system is highly dependent on electricity, it does not work when there is a blackout.

One of the main differences between power vents and direct vents is in their combustion air intake mechanism. A direct vent water heater pulls combustion air from outdoors; therefore, it can be installed anywhere in the house, including basements and closet, without interfering with oxygen levels in the area.

On the other hand, a power vent water heater pulls air from the surrounding areas where it is installed. Therefore, it should only be installed in the basement.

The main advantage of a power vent is that it is quite efficient. In addition, it eliminates any risk of backdraft as the blower or fan ensures that all the exhaust gases are eliminated. On the downside, a power vent heater can be noticeably noisy as the blower or fan produces loud noises when operating.

Tankless water heater costs vary from one model to another regardless of whether it has a power vent or direct vent. Generally, the installation cost for a power vent water heater is about $500 to $1000 higher than that of a direct vent.

Power Vent


  • Completely eliminates the risk of exhaust gas backdraft
  • Does not require a chimney or vertical vent
  • Can be used with horizontal vent pipes


  • Requires a dedicated powerline for the fan or motor
  • Higher energy consumption
  • Noisy operation
  • Costlier and more complex installation

Direct vent


  • Energy efficient
  • Can be installed anywhere as long as there is a vertical vent pipe
  • Easier and cheaper to install
  • Works well even if there is no electricity


  • Require a vertical vent pipe or chimney
  • Slight risk of backdraft, which may lead to carbon monoxide poisoning

Is a Direct Vent Water Heater More Efficient?

A direct vent water heater is both energy and cost-efficient. It does not require to be connected to a power source which reduces the overall operating costs of your gas water heater.

Its operation mechanism is similar to that of an atmospheric vent. It works such that the combustion gases are directed outside naturally through the process of convection. The hot air from the combustion chamber is lighter and more buoyant; therefore, it rises through a vertical vent pipe. In terms of water heating efficiency, it performs as well as power vent heaters with a similar fuel type and GPM.

On the other hand, a power vent is fitted with a blower motor that requires connecting to a direct power line. This increases your overall electricity bill for running a power vent water heater.

It is worth noting that a power vent has superior efficiency when it comes to exhaust fumes elimination. However, a direct vent has a slight risk of backdraft, especially if the venting system is not installed properly compared to a power vent with negligible backdraft risk as long as there is a power supply to the fan.

Can You Use Power Venting on a Direct Vent Water Heater?

No. Each type of water heater is exclusively designed to use the stipulated venting system. Therefore, in case you need to replace the venting system due to improper installation or wear, ensure to stick with the original type.

Keep in mind that any alteration to the original structure of your gas water heater will most likely render the product’s warranties void. Also, tampering with the original design of the water heaters poses risks for fire hazards, electric short-circuiting, or carbon monoxide build-up. It may also disqualify your home during the annual property inspections.

How Long Should a Direct Vent Water Heater Last?

The lifespan of a direct vent water heater mainly depends on its type. Typically, tankless water heaters have a longer life expectancy (up to 20 years) than tank-type water heaters (12-15 years). Ultimately, proper care and maintenance ensure that the water heat lasts long.


Both power and direct venting systems have their pros and cons. When deciding which type to go with for your gas water heater, consider if you have a chimney or vertical flue gas pipe in place. Also, consider your budget in terms of installation and operating costs. Power venting systems are more expensive and require professional expertise to install.

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