Natural Gas Water Heaters: Things to Consider

Natural gas water heaters are a popular choice for homeowners looking for an efficient and cost-effective way to heat water.

With their fast heating times, reliable performance, and low operating costs, they are an excellent choice for households of all sizes.

In this article, we’ll take a closer look at natural gas water heaters, their benefits, how they work, and what you need to know before purchasing and installing one in your home.

Natural Gas Water Heaters: Things to Consider

Whether you’re a first-time homeowner or looking to upgrade your water heating system, this guide will provide you with all the information you need to make an informed decision.

Natural Gas Water Heaters: Benefits and Considerations

Introduction to Natural Gas Water Heaters

Natural gas water heaters are probably the most popular heating systems you can find in North America and Europe.

Natural gas is one of the cheapest forms of energy for residential use; it is clean, affordable, and heats the water quickly and efficiently. The more expensive gas option is propane, not as convenient to get, but still offering benefits as natural gas.

The best known and widely used application for natural gas in homes is for heating and cooking. More than half of the North American and European population uses natural gas for home and water heating.

Since we have an abundance of natural gas available to use for our homes, and with the rising prices, we usually forget that there are many ways how to save on the heating operating costs and service.

Either you are renting a heater or using a new one, you will still have over 20-30%, on average, of your annual household energy bill that goes on water heating.

With the following steps that we recommend, you will save significantly, which will greatly impact your home budget. How much money you can save depends on you and your family members, your habits, and many other criteria; are you using natural gas tankless water heater or tank-type, are you heating water efficiently with the Energy Star recognized units or not.

How Natural Gas Water Heaters Work

Natural gas water heaters work by using a gas burner to heat water in a tank. When you turn on a hot water tap, cold water enters the tank, and the burner ignites, heating the water until it reaches the desired temperature set on the thermostat.

The hot water exits through a pipe, and the thermostat monitors and regulates the temperature. Once the hot water tap is turned off, the burner shuts off, and the remaining hot water is stored until needed again.


Natural gas water heaters offer many advantages that make them an attractive option for homeowners looking for an efficient and cost-effective way to heat water for their household needs. Here are some:

  • Lower operating costs: Natural gas is generally less expensive than electricity, propane and heating oil, so using a natural gas water heater can result in lower monthly energy bills.
  • Faster heating times: Gas models typically heat water more quickly than electric water heaters, so you’ll have hot water available more rapidly.
  • Reliable performance: These heaters are renowned for their dependable performance and ability to provide a steady supply of hot water for household needs. The gas combustion process, which is used to heat water in natural gas water heaters, has been time-tested and proven to be an effective and efficient method for heating water.
  • High energy efficiency: Advanced condensing models are highly energy-efficient with a UEF rating of 0.90 or higher. By comparison, conventional gas water heaters typically have a UEF rating of around 0.60. Some models have earned the Energy Star label, ensuring their energy efficiency and cost savings. They provide reliable and energy-efficient hot water while reducing your energy consumption and carbon footprint.
  • Versatility: They come in a variety of sizes, styles, power, and venting options to suit different household needs, from small apartments to large homes with multiple bathrooms.
  • Reduced carbon footprint: Natural gas is a cleaner-burning fuel than oil or coal, so using a model with low or ultra-low gas emission can help reduce your carbon footprint and contribute to a healthier environment.


  • Installation costs: Installing can be more expensive than installing an electric model, particularly if you don’t already have a natural gas line running to your home.
  • Repairs and maintenance: Natural gas water heaters have more components than electric models, which can make them more complex to repair and maintain. Repairing or cleaning gas units usually requires specialized skills and can be more expensive than for electric models.
  • Safety concerns: Natural gas is a combustible fuel, which means there is always a risk of fire or explosion if the heater is not installed or maintained properly.
  • Environmental impact: While natural gas is cleaner-burning than oil or coal, it still emits greenhouse gases when burned. Natural gas leaks can also contribute to air pollution and pose a safety hazard.
  • Fluctuating gas prices: Natural gas prices can be volatile and subject to fluctuations, which can make it difficult to predict your energy costs from month to month.
  • Limited availability: Natural gas water heaters may not be available in all areas, particularly in rural or remote locations. Electric heaters, on the other hand, can be used anywhere there is access to electricity.

Factors to Consider Before Purchasing

Here are some factors to consider before purchasing a natural gas water heater:

  1. Size and capacity: It’s essential to choose a water heater with the appropriate size and capacity for your household’s hot water needs. Consider the number of people in your home and how much hot water you typically use.
  2. Energy efficiency: Look for a water heater with a high Uniform Energy Factor (UEF) rating. This rating indicates how efficiently the water heater converts energy into hot water. Choosing an energy-efficient and Energy Star model can help save on utility bills.
  3. Cost: They can be more expensive to purchase and install than electric models. The most advanced models, such as condensing heaters, have the highest efficiency rating and lowest operating costs but come at a higher price point.
  4. Venting: These heaters require proper venting to ensure safety and prevent carbon monoxide buildup. Models with the power venting system provide the most installation flexibility.
  5. Features: Look for the models with the state-of-the-art features such as a self cleaning system, ultra-low NOx burner, stainless steel tank, advanced electronics, diagnostics, powered anode rod, high first hour rating and recovery.

Comparing Natural Gas Water Heaters With Other Types

Natural gas water heaters are just one type of water heater available on the market. Here are some key differences to consider when comparing them to other types of water heaters:

  1. Electric water heaters: Electric models are generally less expensive to purchase and install than natural gas models. However, they are often less energy-efficient and can result in higher utility bills over time.
  2. Oil-fired water heaters: Oil-fired models are more expensive to purchase and install than natural gas models. Additionally, they require a separate storage tank for the oil, which can take up more space. However, they may be a better option for homes that do not have access to natural gas.
  3. Propane water heaters: Propane models are similar to natural gas models in terms of cost and efficiency. However, they require a separate propane tank, which can be expensive to install and refill.

When deciding which type of water heater to purchase, it’s important to consider factors such as availability, energy efficiency, and installation costs.

How to Reduce the Operating Costs

  • Keep the temperature at the recommended range of 125 F to 130 F.
  • Run the dishwasher only when it’s full.
  • Rinse dishes with cold, not hot water. 
  • Use cold or warm water to wash and rinse clothes unless hot water is necessary.
  • Don’t run hot water if you don’t need it.
  • Fix any drips you have on the faucet.
  • Check for leaks on the heater or pipes.
  • Insulate the water storage tank with an insulation blanket, being careful not to obstruct the fresh air access or block the pilot light if it’s a gas-powered water heater.
  • Wrap the pipes with the insulation foam.
  • Reduce the shower pressure by installing a low-flow showerhead.
  • Take short showers instead of long baths to conserve hot water.
  • Check the gas burner. A properly adjusted natural gas burner has a blue flame. If the flame is yellow or orange, that means abnormal combustion and not efficient heating.
  • Regular maintenance is needed for efficient performance (like occasionally checking for sediments and flushing the system).

When talking about efficiency, if you have an old electrical and tank tape heater, maybe it is time to consider a natural gas water heater, high efficiency, and Energy Star qualified, such as Rinnai RUR98 or Rinnai RUC98. These models are eligible for government tax credit and rebates.

Also, it is good to be aware of family habits like do you need an abundance of hot water at once. You don’t want to buy an oversized heater as the energy loss is higher, which is a waste of your money.

Natural gas tankless water heaters are probably your best option, since they are not potential heat and energy losses like with the tank-type, and there are models with high efficiency of over 90%.

For your safety, always check the temperature before using hot water and keep the temperature around 120 F.

Selecting Tips

  • Select the type of natural gas water heater you prefer or can use: tankless or tank-typeindoor or outdoor models.
  • Decide what capacity of heater will meet your needs. For tankless models, choose how many gallons per minute the unit produces. For tank-type models, determine the tank capacity in gallons.
  • Select the best venting option: power vent, direct vent, or atmospheric.
  • Consider Energy Star or high-efficiency water heaters. Noritz, Takagi and Rinnai are among the best in their class.
  • Consider buying a condensing water heater or boiler, such as Rinnai.
  • Check the yellow Energy Guide Label, which shows how much it will cost to operate the heater annually.
  • Don’t install the heater yourself. Instead, find a qualified plumber, HVAC technician, or qualified installer who is knowledgeable and familiar with national and local codes and regulations.

Installing and Venting Tips

As mentioned before, when using a natural gas water heater, it is important to ensure safety and adhere to regulations by removing all the by-products of gas combustion outside using approved vents.

Atmospheric-vented models use a vertical vent pipe or chimney for flue gas exhaust. This process works based on physics; warmer flue gases naturally rise through the chimney and exit outside. Before making a decision, we recommend calling an inspector to check the chimney size and features.

If a vertical chimney or venting is not possible, a direct vent or horizontally-vented model can be used. This works in two ways: the flue gas exits through the outside wall, while air for combustion enters through the same vent.

A power-vented option uses an electric fan to assist in pushing the gases outside. This is a good choice if your heater needs to be installed far from the outside wall. Check the building code or manual for the total length allowed. The AO Smith Vertex is a great example of a power-vented water heater.

Safety Considerations

When using natural gas, it is important to follow these safety tips:

  1. Install and maintain a gas water heater properly: Make sure your gas water heater is installed correctly and regularly maintained by a professional to ensure it is safe to use. This includes venting to remove combustion byproducts and proper connection to the gas line.
  2. Use a carbon monoxide detector: Install a carbon monoxide detector in your home to detect any dangerous levels of gas. Carbon monoxide is an odorless and colorless gas that can cause serious health problems or even death.
  3. Keep flammable materials away: Do not store any flammable materials near gas appliances or pipes. Keep them at a safe distance away to reduce the risk of fire.
  4. Check for gas leaks: If you smell gas or suspect a gas leak, immediately evacuate the area and call your gas company or emergency services. Do not use any electrical devices or switch on any lights.
  5. Avoid using gas appliances during a power outage: Gas appliances may not function properly during a power outage, and using them could be dangerous. Use flashlights instead of candles, which can ignite gas leaks.
  6. Know the location of gas shutoff valves: Know where the gas shutoff valves are located in case of an emergency, and ensure that they are accessible and working properly.


In conclusion, natural gas water heaters can be an excellent investment for homeowners looking for an efficient and cost-effective way to heat water.

With their fast heating times, reliable performance, and lower operating costs compared to other heating systems, natural gas water heaters can provide households with a steady supply of hot water while reducing energy consumption and carbon footprint.

However, it is essential to consider factors such as installation costs, maintenance requirements, safety concerns, and availability of natural gas in your area before purchasing a unit.

If these factors align with your needs and budget, then a natural gas water heater may be worth buying.

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