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Tankless Water Heater vs Tank – (Differences / Pros & Cons)

tankless water heater vs tank-Homeowners have many decisions to make daily when maintaining their property. Whether a new home or time for a replacement, shopping for the right water heater is important. Supplying your home with adequate hot water requires an educated decision that needs to be carefully considered.

After figuring out how frequently your home uses hot water and the demand for the use, there is a decision to go with a tankless vs. tank water heater in your home.

No one wants to go halfway through a hot shower to have it suddenly turn cold! Nor do they want to dish out thousands of dollars to reconstruct pipes and connections in your home just to change over to a different type of water heater. There are some great things and then some not so great things about each option. After you see some of the reasonings, then you can make an informed decision as to what works best for you.

Energy Sources

Both options of the tanked and tankless water heaters have several types to select from. With the tank water heaters, there are three types that could work for you:

  • Natural gas
  • Electric
  • Propane

For the tankless water heaters, they can operate on gas or electric. There are two options:

  • Non-condensing
  • Condensing

With the different types to select from, you should research what type of water heater would work best for your existing pipes. Determine if you can keep the existing pipes and reconnect the same type of water heater that you’re replacing. If you are looking to switch over to the opposite of what you already had or in a position to start with a new connection, figure out your peak usage. Whether it’s a tank water heater or tankless, finding out your daily usage will determine not only the size of your water heater but also if either a tank or tankless is best for you.

Tankless Water Heaters

tankless-water-heatersTankless water heaters heat water directly without the use of a storage tank. Either a gas burner or an electric element heats the water. It uses high-powered burners to rapidly heat water as it runs through a heat exchanger and deliver it directly to your faucets or shower without storing it in a tank.
Tankless water heaters are more energy efficient for your homes because it is not constantly running to maintain hot water.

According to energy research done by, if you are using a 40-gallon tank of hot water or less, your energy demand is typically less than 50 percent with a tankless water heater compared to a water heater tank. Water heaters normally come with an Energy Star with the exact information on how much you should see in savings over time when using a tankless water heater.

Types of Tankless Water Heaters

Like the tank water heaters, you can go with a gas or electric option for tankless water heaters. Gas tankless water heaters produce a higher flow rate than that of electric water heaters. A flow rate is just the gallons used per minute. When determining the size of your tankless, you should think of how many devices will run and then figure out how many gallons per minute is used. If you are running your faucet and a shower, add up both of those flow rates and search for a tankless water heater that will be able to have a flow rate of them combined.

  1. Electric Tankless Water Heaters

    Once the flow rate is determined, you can move on to what type of tankless would work best for your home. The electric tankless is an option since the upfront cost is normally in the hundred-dollar range or more. It typically won’t exceed into thousands of dollars for the unit, depending on the brand and size. It is cheaper to install an electric tankless water heater since it does not require any venting. The space saver option of a tankless is with the electric types. With no venting required for hook up, this tankless can be placed in many places within your home. The flow rate for electric tankless water heaters range from 3 to 8 GPM and there is no repeat maintenance on these units.

  2. Gas-Powered Tankless Water Heaters

    The gas-powered tankless water heaters have a higher upfront cost than electric. They also require ventilation, so the installation cost is more. It may even require professional assistance since you are connecting to a gas power line. With the gas option, you are leaving a slightly bigger environmental footprint than with the electric option. In addition, the pricing for usage will fluctuate to what the rate is in your area for natural gas. Maintenance is something else to consider when dealing with gas water heaters. Typically, gas water heaters require annual maintenance, which is something to consider when price comparison with the electric tankless water heaters. Gas powered tankless water heaters have a better flow rate, typically starting at 8 GPM or more. These would be a great option for servicing a larger home with heavy hot water usage.

Tankless Water Heater Pros & Cons


  • Life expectancy of 20 years; which is almost twice the life of the tank water heaters
  • Space saver; can go in smaller spaces since there is no tank
  • Quick delivery of hot water; receive 2 to 3 gallons of hot water per minute


  • Cannot handle too many simultaneous users on one water heater
  • Upfront purchase price is typically more than tank water heaters
  • Gas tankless water heaters may have a constantly burning pilot light
  • May require major changes to home to accommodate the water heater

With the tankless water heaters coming in various sizes, if you do have several simultaneous uses, you may consider purchasing water heaters and placing them in certain areas to handle specific things. For example, you may want to have a separate water heater for the kitchen area to support the sink and dishwasher unit separately from the showers and laundry. This is just dependent on your usage and of course if your home will support it. Regarding the pilot light issue, you may be able to turn the pilot light off when not in use or go with a different type of tankless water heater altogether.

Tank Water Heaters

tank-water-heatersA tank water heater is insulated which typically holds 30 to 50 gallons of water. A water tank simply fills and always maintains a certain amount of hot water, even when not in use. The issue arises when multiple uses for hot water occurs and the tank runs through all its stored water. Depending on the brand you are purchasing, the water tank must take time to not only refill, but it must bring the water to the set temperature. This may result in cold water coming out for your shower or sink for a brief period.

Types of Water Tanks

Depending on your current connections, you can select a natural gas water heater, electric or propane. These options are usually more dependent on what is allowed where you live. For example, an electric tank water heater may be a better buy in some regions where natural gas is limited or too expensive. There are also many high-quality electric water heater tanks that can better gauge water use to know when it needs to be refilled. A gas water heater that is powered by natural gas or propane is the other popular choice for water tanks. For most, it is easiest to replace with the same type of tank that was connected previously as opposed to changing over from electric to gas due to using existing pipelines.

Evaluate Your Budget

Gas water heater tanks typically can last anywhere from 8 to 15 years. They may have a higher setup cost, but homeowners can see savings in their utility bills over time compared to electrical water tanks. Natural gas water tanks are economically and environmentally friendly. Installation of this type of heater is typically simple enough for self-installation and may not necessarily need a professional to install, which saves on upfront cost. Overall, the gas water heater tank uses approximately 50 percent less energy than the electric option with less maintenance over time. Electric water tanks are the most common as they work in regions where gas may be limited or too expensive as an option. There are many tanks that are digitally advanced. They work to improve on refilling with hot water at a faster pace, however, it is only as fast comparable to other water heater tanks.

What are Your Expectations?

The first-hour rating is an important way to know how well the water heater will work for your home. The first-hour rating is when the unit reads how much hot water is delivered in a set amount of time. Basing the water heater off how many gallons it can hold alone won’t help if the tank cannot handle heavy usage within one hour. For example, you must know how many hot gallons of water can be supplied within an hour. If you have an 80-gallon tank and a family that normally uses half of that for one hour, then if the FHR is 30 for the water heater, it’s not ideal to purchase.

Tank Water Heater Pros & Cons


  • Lower initial cost to install
  • Simpler to operate so less costly maintenance and repairs
  • Heats large volumes of water


  • Wait time for tank to refill
  • Doesn’t last for several consecutive uses
  • Only lasts 10 to 15 years; half the time than tankless
  • Frequently replace
  • Higher energy bill

Should You Buy a Tankless Water Heater or Tank?

Deciding on which type of water heating technology is best for you, important! With water heaters lasting 10 to 20 years, this purchase isn’t frequent, but you will live with the decision every day. While some are not able to easily switch from tank to tankless or vice versa if you do have the flexibility to start with the best option for you, make sure you do your research. It all starts with the demand of use of hot water within your home. The needs of a one-bedroom condominium may be different than that of a 6-bedroom home. There may be heavier use in the mornings running showers back to back along with faucets or dishwashers that all would require a more reliable water heater.

The tank water heaters have a lower upfront cost and may not require costly installation. There is a limitation on where the tank water heater may go within your home, with it normally being hidden in a closet, basement or laundry room. Compared to the tankless, the tank water heater will have a higher energy bill due to its continuously heating water, even when not in use. With the option for natural gas or an electric tank water heater, you do see some benefits to selecting the tank option. These do normally require more frequent replacing since their expectancy is 10 to 15 years.

Choice of Cost

The tankless water heater does cost a little more upfront. The upside to that is it doesn’t have an annual maintenance need like the tank water heaters. The tankless water heater can help lower your overall utility bill since it is not constantly running to maintain hot water. With it heating water only upon usage, it’s not running idle all day.

There are different types of tankless water heaters to select from like condensing and non-condensing as well as if you are looking amongst gas or electric. With the gas tankless water heater, it may have an even pricier installation cost. The plus side to the gas water heater is the increased GPM. This gives you at least 8 GPM or more compared to the electric 3 to 8 GPM it normally provides. Deciding on a tankless vs. tank water heater can be quite straightforward once you go through the basics.

Whichever you decide to select, the main goal is to be able to provide consistent hot water for your home without the disrupting cold blast. Overall savings can happen on either type once you determine the cost of set up and know your hot water needs.

by Water Heater Mag

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