John Wood Water Heaters: Review and Buying Tips

John Wood gas water heaterJohn Wood
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A detailed review of the popular John Wood water heaters. Explore storage tank and tankless heaters powered by electric energy, propane, and natural gas, including the top models and their features.

Either buying a traditional cylinder type or a new and advanced tankless type, the John Wood Company can meet all your needs for hot water, helping you save money and reduce gas emissions.

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John Wood water heaters: Selecting the right type

John Wood gas-powered water heaters

Customers can buy gas water heaters from John Wood depending on the availability of the fuel source - natural or propane gas, and using one of two technologies; traditional tank-type or tankless. All the gas tank-type models are coming from the ProLine and ProLine Master series.

John Wood has a great selection of gas-powered models, including atmospheric vented, direct, power, direct vent type, and the most efficient gas model, Polaris.

Most of the tank-type models are equipped with the industry-standard Flammable Vapor Ignition Resistant technology or short FVIR. The FVIR safety system is known as the Flame Guard system in atmospheric vent models, Flame Safe found in direct vent models, and Superflue used in power vent units.

All these systems are designed to shut down the heater if the flammable vapors from paint, chemicals, and solvents are detected inside the combustion chamber, protecting the users and home.

Atmospheric vent

Gas water heaters with atmospheric venting are designed as natural gas and propane or LP powered, both using the chimney to move the products of combustion out and the surrounding air for combustion. The main features are the gas valve, capable of diagnosing the problem, enhance performance and safety, a thermopile that can withstand different weather conditions, and the Turbulator, a specially designed dip tube used to help in reducing the sediment build-up.

Atmospheric-vented heaters come in two groups, with lower and higher efficiency. If you decide to buy an atmospheric type, look for the models with an installed flue damper (XE) as they come with higher efficiency, making them Energy Star compliant. These Energy Star models are available in two sizes only; 40 and 50 gallons. If you need a unit with a different tank size, 30, 60, or 75 gallons are the options you have, and they come with low efficiency.

Only the ProLine Master model comes with a longer warranty of 8 years.

Power vent

John Wood water heaters with power venting (XE models) are also designed as high-efficiency units that utilize advanced features built for professionals and tanks with a large capacity, with and without condensing technology.

The best John Wood power vent comes from the High-Efficiency series and is known as the Envirosense model. This 50-gal unit is designed with the helical condensing heat exchanger resulting in 94% efficiency and recovery rate. Check the review of the power vent models here.

Power direct vent

Power direct vent water heaters (XE) are Energy Star qualified using the outside air for combustion and ultra-quiet blower to remove the gases out. What makes them safe for indoor use is the sealed combustion chamber, so the indoor air stays intact. John Wood offers two popular sizes that are Energy Star compliant; 40 and 50-gallon with a flexible venting system and up to 180 ft. pipe length that can run either through the roof or outside wall.

The best power direct model from John Wood is the 50-gal Envirosense that comes from the High-Efficiency group as its thermal efficiency is ultra-high - 96%. High efficiency is the result of the advanced design; helical condensing heat exchanger, power direct venting, and advanced electronics. Extremely high energy factor means less energy loss and more savings for you. It is also available as the 75-gal model.

Direct vent

The greatest advantage of the direct-vented water heaters from John Wood is not only the thermopile or the advanced gas valve with diagnostic capabilities but the reason that the external power supply is not required, making it electricity independent. This type is mainly installed close to the external wall with the horizontal termination. If you live in a house without a chimney, this is the water heater type for you. Read more...


In addition to the Envirosense models mentioned above, there is another group of ultra-efficient models, known as Polaris.

Polaris advantage over other standard type models is that Polaris utilizes the submerged combustion chamber and spiral flue, resulting in 95-96% thermal efficiency and ultra-low NOx emission – great for regions with the strict emission regulations.

Also, the stainless steel tank and other commercial-grade components make Polaris a very durable and reliable unit - very well worth buying. This is a condensing unit, which can be used for both potable water and space heating.

John Wood electric water heaters

Electric water heaters from John Wood are found in two groups; conventional, tall size with the tank size from 50 to 80 gallons – ProLine series, and Space Saver line.

ProLine and ProLine Master water heaters are available in two sizes only. They utilize commercial-grade components such as the TankSaver technology that provides quality tank protection and heavy-duty anode rod against corrosive water effects. The ProLine Master series comes with a 2-year longer warranty, providing a maximum of 8-year worry-free use.

The Space Saver group is the group that contains only water heaters with the lower capacities, from 2.5 gallons, and Lowboy up to 50 gallons, designed for homes with the limited space, apartments, cottages, offices, mobile homes, etc.

Smaller models with one heating element are ideal for point-of-use applications, while larger ones, with two elements, can be used in applications with higher hot water demand. Customers can also choose a water heater with side or top water connections.

They come with a warranty of 6 years.

John Wood oil-fired water heaters

John Wood oil-powered water heaters come with the common mounting design so they can fit many types of oil burners and a unique design combustion chamber that maximizes heat transfer and reduces energy loss. Models with 32 and 50 gallons are the only two sizes available for heating the home space and residential water.

John Wood tankless water heaters

John Wood tankless water heaters are using tankless technology from the well-known and reputable manufacturer Takagi. The tankless design allows an endless hot water delivery, in continuous supply, not only for one but multiple fixtures simultaneously.

These heaters heat water instantaneously, and due to the tankless design, they provide hot water on demand. The best models are ultra-efficient and Energy Star approved and are also known as condensing water heaters, where the energy factor can reach a high of 0.95. You can find more info about tankless models in this article.


The John Wood manufacturer is a Canadian company subsidiary of GSW, acquired by AO Smith in 2006. It offers a wide variety of water heaters for any household, budget, installation requirements, and house type and is sold mainly in Canada.

If looking for an affordable unit with average energy efficiency, you can get one for a few hundred dollars. On the other hand, if you want the top-of-the-line model, condensing tankless is what you should go for, or if you prefer traditional, tank-type Polaris or Envirosense is the right pick, but be ready to pay for the quality.

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