
If you’re looking for a new water heater, you may be debating between a tankless water heater vs. a tank water heater. These two options broadly encompass most of the available water heaters on the market. If you don’t know the difference between these two options, it can be challenging to choose between them.
What’s the real difference between the two options?Is a tankless water heater better than a tank one?
This choice shouldn’t be taken lightly because the average Canadian home uses around 75litres of hot water daily. You may not often think about your home’s hot water, but it’s a crucial part of daily life for both necessity and comfort. This guide will answer all your questions about the differences (and similarities) between traditional andtankless water heaters, so you can determine which is the best for your family and home.
What Is a Tankless Water Heater?
Tankless water heaters are a relatively new invention, with the first systems patented in 1929 and gaining popularity during the 1990s. On the other hand, traditional tank water heater systems were designed in 1889 and quickly became home mainstays starting in the 1920s. But, of course, it wasn’t until the 1940s that water heaters took off, correlating with the rise of electricity in homes.
You may hear tankless units called on-demand water heaters — an apt name because they work by heating water as needed. Anytime you turn on a faucet and require heated water,tankless systems generate as much hot water as you need. As a result, tanklesswater heaters can theoretically provide an unlimited amount of hot water without ever running out, and they’re surprisingly energy efficient while doing it, too.
What Is a Tank Hot Water Heater?
A tank hot water heater is the most common and traditional option in Canada and the United States. This is likely what comes to mind when you think of water heaters: a tank (usually fairly large) with several pipes running off it. If your home has one of these water heaters, you’ll probably find it in your basement, but it can occasionally be on the ground level in a water closet (generally for homes without a basement).
The “tank,” called a vessel or container, typically holds between 75 and 400 litres of water at a time. The water is stored in the vessel and heated all at once to supplyyour hot showers, dishwashingand laundry needs. The water may be heated using gas, propane, or electricity, depending on the model of water heater. Regardless of how the water is heated, tank water heaters tend to be efficient because they can utilize energy slowly to preserve the heat of the water.
Pros and Cons of On-Demand Water Heater vs. Tank Water Heater
Both water heater types come with their own sets of pros and cons. Although we’ve provided a more in-depth breakdown below, we’ll briefly discuss these benefits and downsides in a scannableformat here.
Tankless Water Heater
The benefits of a tankless water heater include:
- Save money because they don’t consume energy during the day to keep water hot
- Virtually limitless hot water available at any time
- Better choice for tight spaces
- Can be placed almost anywhere in your home (versus being stored in the basement or water closet)
- Won’t burst during cold fronts
- Virtually zero wait for hot water when you turn on the tap
- Less maintenance is required for theupkeep
The downsides of a tankless water heater are:
- High initial costs for installation
- Having to retrofit your plumbing (and maybe your electrical system) to install
- Zero hot water reserves if the electricity goes on
Traditional Water Heater
The benefits of traditional water heaters include:
- Comparatively low installation costs
- Compatible with other systems in the home
- A small hot water reserve during power outages
- Still works during power outages, if powered by gas or propane
- Typically provides a higher flow rate versus tankless options
The downsides of traditional tank water heaters are:
- Higher energy usage becausethey need to keep the water in their tanks hot when not in use
- Limited amount of hot water available
- Require larger spaces, so they’re typically allocated to the basement
- Can burst during freezing weather
- A short wait before hot water comes through the faucet
- Require regular maintenance and upkeep to work properly

Tankless vs. Tank Water Heaters: An In-Depth Breakdown
Below, you’ll find a more in-depth breakdown of how tankless vs. tank water heaters compare.
Cost
Regarding initial costs, traditional water heaters are significantly cheaper for a few reasons. For starters, the systems themselves are cheaper. But it’s also important to understand that your home is most likely already designed to integrate with a traditional system, meaning there aren’t any additional installation costs.
On the other hand, tankless water systems often require you to retrofit your plumbing, and you may need some electrical workbefore installation, too. This can significantly driveup the initial costs of a tankless system, makingit a poor choice if you’re a Canadian homeowner on a tight budget.
Long-term costs tell a different story. Tankless systems require less maintenance, and they can last up to twice as long as traditional systems. Paired with their energy efficiency, tankless systems areless expensive over their total lifetime compared to tank water heaters.
Energy Efficiency
The energy efficiency of either water heater type can vary significantly based on the specific brand and model you choose. However, tankless water heater systems are usually more energy efficient because they don’t need to keep the water heated when not in use. Instead, energy is consumed only when the faucet in your kitchen, bathroom or utility room is turned to the hot setting.
Lifespan
A traditional water heater is estimated to last 10 to 15 years with regular upkeep and maintenance. But tankless systems last an average of 20 years, with some lasting significantly longer. In terms of expected usable lifespan, tankless systems are a clear winner.
Maintenance
Both traditional and tankless hot water systems should have annual maintenance to ensure they’re working properly — even if it’s just a yearly inspection. Generally, the care required for a traditional system is more extensive, making it more expensive.
Space Requirements
Tank waterheaters take up a lot of space because the vessel holding the water is large. These tanks also require a safe boundary where nothing else should be placed or installed. On the other hand, tankless systems require significantly less space and can be installed almost anywhere in your home.
Tank vs. Tankless Water Heater: Which Is Better?
There isn’t a clear one-size-fits-all answer to the tank vs.tankless water heaters debate. Instead, it’s a matter of weighing the pros and cons to determine the best choice foryou and your home. For example, if having hot water on demand is the most crucial factor for you, a tankless water heater system is the best choice. If cost is the primary issue, a traditional tank water heater is the clear winner.
Get a Quote on a New Water Heater System Today
Buying your home’s new hot water heater system is a substantial investment. There’s no straightforward right or wrong answer in the battle of tankless water heater vs. tank water heater. But choosing the right one for your unique preferences and needs using the information within this guide can significantly affect your overall comfort while at home. No matter your choice, you canget a free quote on a new waterheater system today by filling out a few simple questions.
Water Heater Frequently Asked Questions
How can I tell if my hot water heater needs to be replaced?
One of the greatest indicators that it’s time to replace yourwater heater is that it’s reached the end of its estimated usable lifespan. If your water heater has broken, compare the repair and replacement costs. If a repair costs 60% or more of replacement costs, purchasing a new unit is better. Other indicators that it’stime to replace your water heater include rising energy costs, loud noises, weird smells, and lowered efficiency.
Can you run out of water with a tankless water heater?
You shouldn’t run out of water if you have a tankless water heater system. If you do have a tankless system and run out of hot water, that indicates you need to call an HVAC repair technician.
Will a tankless water heater run up my electric bill?
A tankless water heater should actually lower your electric bill. The reduction in energy costs varies based on numerous factors and may only be a slight (and barely noticeable) amount. However, your electric bill certainly shouldn’t go up after a tankless water heater installation. If it does, you’ll want to schedule an appointment with an HVAC technician to determine the cause behind the rising energy rates.
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FAQs
Tankless Water Heater vs. Tank Hot Water Heater? ›
According to Energy.gov, “For homes that use 41 gallons or less of hot water daily, demand (or tankless) water heaters can be 24% to 34% more energy efficient than conventional storage tank water heaters.” Tankless water heaters (if gas-fired) will save homeowners over $100 annually the longer they remain in service.
Is it better to have a tank or tankless water heater? ›According to Energy.gov, “For homes that use 41 gallons or less of hot water daily, demand (or tankless) water heaters can be 24% to 34% more energy efficient than conventional storage tank water heaters.” Tankless water heaters (if gas-fired) will save homeowners over $100 annually the longer they remain in service.
What is the downside of a tankless water heater? ›One of the main drawbacks that prevent people from making the switch to a tankless water heater system is that they cost about three times as much to purchase and install as a tank-style water heater. According to HomeGuide, the average cost to install a tankless water heater ranges from about $800 to $3,500.
Is it worth it to replace a water heater with a tankless water heater? ›For many people, the long-term benefits of tankless heaters more than compensate for their initial expense. A tankless heater can be up to 34% more efficient than a traditional water heater. This increase in efficiency can amount to annual savings of over $100, depending on the type and size of the heater.
What uses more gas tankless or tank water heater? ›The EPA estimates that a tankless water heater uses up to 34% less energy than a storage tank water heater if you use 41 gallons or less of hot water daily. If the household uses closer to 86 gallons of hot water a day a tankless water heater will be up to 14% more efficient.
What is not a benefit of a tankless water heater? ›The biggest downside of tankless water heaters is their higher initial cost. A good quality tankless heater will run you more than a traditional storage-tank model, although the savings in energy costs over time can make up for this difference.
Can you run out of hot water with a tankless water heater? ›You can't run out of hot water with tankless water heaters - unless, of course, the power supply is off or goes out. However, a tankless water heater can have trouble keeping up with demand if too many things require hot water all at once.
What is the most common issue with tankless water heaters? ›The commonest complaint we get with tankless water heaters is that they don't seem to provide hot water as quickly as expected. Like most tankless water heaters, if your water heater does not have a buffer tank or a recirculation pump, it may take a minute or two for the water to heat up before it comes out of the tap.
Why does it take so long for hot water with a tankless water heater? ›With tankless water heaters, there can be a short delay as hot water must travel from the heater to the open outlet. If this is a major concern, a homeowner can try a few methods such as installing a water recirculation system or a secondary water heater close to the affected faucet.
How big of a tankless water heater for a family of 4? ›36 kW 6.2 GPM Residential Electric Tankless Water Heater, Ideal for 4 Bedroom Home, Up to 8 Simultaneous Applications.
Why not to go tankless? ›
Because tankless water heaters, even gas models, need electricity in order to run and regulate, if the power goes out, then so does your hot water. If you live in an area prone to outages, a tankless water heater may not be the best choice.
Where should tankless water heater not be installed? ›You should avoid installing your tankless water heater in a location prone to excessive humidity, moisture, or dust, or in an area where it may be splashed with water or other liquids. Do NOT install under water pipes or air conditioning lines that might leak or condense moisture that could then drip onto the heater.
How much does it cost to switch from a water heater to a tankless water heater? ›The national average for tankless water heater installation cost is around $2,800. Depending on the model, the units themselves usually cost between $500 and $2,000, with installation adding another $500–$1,500. Therefore, the overall cost for installation ranges from $1,200–$3,500.
What are the pros and cons of a tankless water heater? ›Pros of tankless water heaters | Cons of tankless water heaters |
---|---|
High efficiency | Limited flow rate |
Long-term savings | High upfront cost |
Environmentally friendly | Can require prior setup work |
With proper maintenance and water treatment, a tankless water heater can last anywhere from 12 to 30 years.
Are tankless water heaters noisy? ›Tankless water heaters will all make some noise when starting up and heating water, but the noise levels are usually reasonable and not cause for concern.
Why would I want a tankless water heater? ›Tankless water heaters, also known as demand-type or instantaneous water heaters, provide hot water only as it is needed. They don't produce the standby energy losses associated with storage water heaters, which can save money.
Can I take a long shower with a tankless water heater? ›With a tankless water heater, you can take a shower, use the dishwasher, and do laundry all at the same time without losing hot water.
How many showers can a tankless water heater run? ›A unit heating more than 7 gallons per minute can typically handle two showers and a large appliance. *Important to note: Tankless units do not literally provide “instant hot water” – the hot water still takes time to flow from the unit to the faucet.
Can you run 2 showers with a tankless water heater? ›Yes. You must choose the proper model to suit your home's hot water needs, which is based upon the maximum flow of hot water you need at any one time. You can buy tankless water heaters that are capable of handling one shower at a time and others that can sustain a maximum of two showers operating at the same time.
Does a tankless water heater mean endless hot water? ›
Tankless water heaters are able to provide endless hot water because they heat your water on-demand instead of from a tank (which can eventually run out of hot water). After the demand for hot water has been fulfilled, the water heater turns off and the heat exchanger cools back down.
Does a tankless water heater mean unlimited hot water? ›In contrast, a tankless heater can provide unlimited hot water because it maintains 2-8 gallons per minute (gpm) of hot water as long as water is flowing through it.
Why does my tankless water heater get cold after a few minutes? ›Low water pressure is one of the most significant reasons why the tankless water heater suddenly cold during the shower. The flow within your device is lower than the activation flow rate required, resulting in the closing down of the gas burner or it may not ignite the burner at all.
Can I replace my 40 gallon water heater with a tankless water heater? ›This is simply due to the fact that tank water heaters are constantly heating and reheating 40-75 gallons of water while your tankless only operates on demand. With the help of a professional you can easily convert from a tank water heater to a tankless water heater.
How many bathrooms can one tankless water heater handle? ›SELECTING A TANKLESS WATER HEATER
For a home with 1 bathroom, we recommend 6-7 GPM; 2 bathrooms, 8 – 9 GPM; and 3+ bathrooms, 9-11 GPM. In our experience, smaller 4-5 GPM units are suitable for studio apartments and small one bathroom homes or other application specific needs.
When it comes to gas lines and tankless water heaters, size does matter. We recommend that the gas line size for your tankless water heater be ¾-inch. However, if the length of the gas line is short enough, a ½ -inch gas line would work too.
Can bacteria grow in tankless water heater? ›Because there's no tank on electric tankless water heaters, water doesn't have a chance to sit still in your system and collect bacteria or calcify. Water goes directly from your pump, through the system, through the pipes and comes out at your faucet.
Does tankless increase home value? ›If you are looking to increase the value of your home, adding a tankless water heater to your features is a great place to start. According to a study conducted by Zillow, homes with tankless water heaters sold for 4% more than their expected value.
Why is the installation of a tankless water heater so expensive? ›Tankless water heaters feature more components because the process they use to heat water is a bit more intricate. You'll find a flow sensor, computer board, gas valve, heat exchanger, burner, fan, and bypass valve in every gas tankless water heater. But complexity is only one piece of the puzzle.
Do you need a pan under a tankless water heater? ›Every major brand of tankless requires a drain pan if the unit is installed where a leak can cause damage to the home or building. Architects and engineers understand that when a tankless water heater reaches the end of its life it will likely leak, just like a tank.
How much room do you need around a tankless water heater? ›
It is true that tankless water heaters do not require a lot of space. A large unit requires an area no larger than 24 inches square and ex- tends from the wall by about 8 to 10 inches.
What's the price difference between a tankless water heater and a regular water heater? ›Tankless water heaters have a higher purchase cost than a traditional storage tank. The cost of a tankless water heater can range anywhere from $2,000-$4,500 compared to a storage tank water heater which ranges from about $500-$800.
How long does it take a tankless water heater to heat up? ›Tankless units take about 15 seconds to bring water up to temperature, but you still have to wait for that hot water to arrive at your shower head or faucet, just as you do with a tank-type heater.
Do you have to flush a tankless water heater every year? ›Over time, a tankless water heater may accumulate mineral build up which can erode the walls inside your tank's heating chamber. To properly maintain and clean your tankless water heater, it's important to flush those mineral deposits at least once a year.
How much money a month does a tankless water heater save? ›The U.S. Department of Energy estimates gas-fired tankless heaters save an average of $108 in energy costs per year over their traditional tank counterparts, while electric tankless heaters save $44 per year.
Which lasts longer gas or electric tankless water heater? ›Electric vs Gas Tankless Water Heaters
Electric tankless water heaters are typically around 98 percent or more efficient while gas tankless water heaters are around 80-85 percent efficient. A gas tankless water heater can be cheaper to run and will typically last longer.
Why Is My Tankless Water Heater Making a Banging Noise? Noise in a tankless water heater is normal when the water is heating up. If the noise is happening at times of low use, like nighttime, it's probably time to take a closer look. The most common cause of knocking or banging noise is sediment buildup.
What happens when a tankless water heater goes bad? ›A tankless system can also fail in the ways that a standard gas-powered water heater or furnace can fail. The gas jets can become dirty and fail to ignite fully—or ignite at all. If the electronic ignition system breaks, the water heater won't come on and you'll end up with no hot water at all.
Are Rheem tankless water heaters noisy? ›One of the reasons that people have favored the Rheem/Ruud heat pump water heaters is because they are quiet. Rated at a low 49 dB, you could install one in most places around the house and not notice it operating.
Do tank or tankless water heaters last longer? ›The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset their higher purchase price.
What size tankless water heater do I need for a family of 4? ›
36 kW 6.2 GPM Residential Electric Tankless Water Heater, Ideal for 4 Bedroom Home, Up to 8 Simultaneous Applications.
Which is cheaper to operate gas or electric tankless water heater? ›At present, a natural gas tankless water heater is about 10-15% cheaper to operate than an electric tankless heater. A tankless electric heater is generally cheaper than a propane tankless heater.
How much cheaper is it to run a tankless water heater? ›Cheaper to operate — Using a tankless hot water heater can save you hundreds of dollars per year. A typical 40 gallon electric water heater will cost anywhere from $200 per year for the most efficient models to $800 for the least efficient models, tankless models often cost less than $100 per year to operate.
Why switch to tankless water heater? ›The Pros of Switching to a Tankless Water Heater
Avoid the risk of flooding due to a ruptured tank. Tankless water heaters consume less energy because they only need enough power to heat water as it's needed. Tankless water heaters are more efficient and don't experience standby heat loss.
Tankless water heaters have the longest life expectancy of all three types at more than 20 years. Many parts can easily be replaced based on the heater's design, elongating the water heater's lifespan.
Do electric tankless water heaters need to be vented? ›Unlike gas or propane tankless water heaters, electric tankless water heaters do not need venting because they use electric burners to heat water rapidly. Since no natural or propane gas is used, no venting is needed.
How many bathrooms can a tankless water heater handle? ›SELECTING A TANKLESS WATER HEATER
For a home with 1 bathroom, we recommend 6-7 GPM; 2 bathrooms, 8 – 9 GPM; and 3+ bathrooms, 9-11 GPM. In our experience, smaller 4-5 GPM units are suitable for studio apartments and small one bathroom homes or other application specific needs.
Pros of tankless water heaters | Cons of tankless water heaters |
---|---|
High efficiency | Limited flow rate |
Long-term savings | High upfront cost |
Environmentally friendly | Can require prior setup work |
Requirements for electric tankless water heaters:
Voltage — Many retailers sell units that will accommodate 110V, 120V, 208V, 220V, 240V, and 277V. Amperage — Different electric water heaters will have various requirements in amp draw.
Tankless water heaters have a higher purchase cost than a traditional storage tank. The cost of a tankless water heater can range anywhere from $2,000-$4,500 compared to a storage tank water heater which ranges from about $500-$800.
What is the downside of an electric water heater? ›
Electric Heater Disadvantages
The disadvantages to a water heater fueled by electricity are: Usually has a more expensive maintenance cost. Won't work during power outages unless there is a power source. Heats less water per hour.