Tankless water heaters, also known as demand-type or instantaneous water heaters, provide hot water as it’s needed. They’re energy-efficient, easy to install, and provide a multitude of other benefits.
In this article, we will delve into the world of tankless water heaters, exploring their advantages, working principles, and pointers on how to choose the right one for your home.
Table of contents
What are tankless water heaters?
Tankless water heaters, also known as on-demand water heaters, are devices that heat water directly without the need for a storage tank. When a hot water tap is turned on, cold water travels through a pipe into the unit, where either a gas burner or an electric element heats the water. This means you have a constant supply of hot water whenever you need it without waiting for a storage tank to heat up.
Because these heaters only heat water as it’s being used, they can be more energy-efficient than traditional storage tank water heaters. They come in various sizes for different needs, from point-of-use models that can handle one faucet or shower at a time to whole-house models that can supply hot water to multiple outlets simultaneously.
7 Revolutionary benefits of tankless water heaters you need to know
1. Energy efficiency
Tankless water heaters are highly energy-efficient. They operate on demand, meaning they only heat water when it’s needed, thus saving on the energy that conventional water heaters waste by keeping a full tank of water hot. This efficiency can translate to significant savings on your energy bills over time. According to the U.S. Department of Energy, for homes that use 41 gallons or less of hot water daily, tankless water heaters can be 24–34% more energy efficient than conventional storage tank water heaters.
2. Infinite supply of hot water
When you have a tankless water heater installed, you get an endless supply of hot water. This means no more cold showers if you’re the last one in line! Because these systems heat water on demand, as long as you have water, you can have it hot. This feature can be especially beneficial for large households where the demand for hot water is high.
3. Space-saving design
Unlike traditional water heaters that require a significant amount of storage space for the tank, tankless water heaters have a compact design that can be installed in small spaces, including closets, under cabinets, or even outdoors with an anti-freeze kit. So if you’re looking to free up some space in your home or considering a tiny house lifestyle, a tankless water heater might be the perfect fit.
4. Long lifespan
Tankless water heaters generally have a longer lifespan than their traditional counterparts. While a conventional water heater typically lasts 10–15 years, a tankless model can last up to 20 years or more with proper maintenance. This longevity can offset the initial cost of the unit and save you on replacement costs in the long run.
5. Clean, fresh water
With a tankless water heater, you always get fresh, clean water. Traditional water heaters store hot water in their tanks, where it can sit for hours or even days before being used. This can lead to rust and scale buildup inside the tank that can contaminate the water. But because tankless models heat water directly without the use of a storage tank, you avoid this problem altogether.
6. Lower risk of water damage
Since tankless water heaters don’t store water, there is no chance of serious water damage from a leaking or burst tank. This can save you from potentially costly repairs and cleanup associated with such incidents.
7. Environmentally friendly
Finally, by saving energy through their on-demand operation and by lasting longer than traditional models, tankless water heaters are an environmentally friendly choice for home heating systems. Plus, many models are made with recyclable parts, further reducing their environmental impact when they’re eventually replaced.
Understanding the working principle of tankless water heaters
Tankless water heaters work on the principle of heating water directly as it flows through the unit, negating the need for a storage tank. When a hot water tap is turned on in your home, cold water is drawn into the heater. A flow sensor within the unit detects this water intake and ignites the burner (in a gas-powered model) or turns on the electric heating elements (in an electric model).
The water then circulates around a heat exchanger, where it’s heated to a predetermined temperature before being sent to your faucet or appliance. The heating process stops when you turn off the hot water tap, ensuring energy is used only when hot water is needed. This on-demand heating methodology makes tankless water heaters highly efficient and cost-effective.
Comparing tankless water heaters with traditional water heaters
| Aspect | Tankless Water Heaters | Traditional Water Heaters |
|---|---|---|
| Energy Efficiency | High (only heats on demand) | Lower (keeps water hot) |
| Lifespan | Up to 20 years or more | 10-15 years |
| Space Requirement | Small, compact | Requires considerable space for tank |
| Hot Water Supply | Unlimited | Limited by tank size |
| Cost | Higher initial cost, lower operational cost | Lower initial cost, higher operational cost |
| Risk of Water Damage | Less (no storage tank to leak or burst) | More (possible tank leaks or bursts) |
| Environment Impact | Lower (more efficient, less waste) | Higher (less efficient, more waste) |
- Energy efficiency: Tankless water heaters only heat water when it’s needed, making them highly energy-efficient. In contrast, traditional water heaters keep a full tank of water hot at all times, which can lead to energy waste.
- Lifespan: With proper maintenance, tankless water heaters can last up to 20 years or more, whereas traditional water heaters typically last about 10–15 years.
- Space requirement: Tankless water heaters have a compact design that can fit in small spaces. Traditional water heaters require a considerable amount of space for the tank.
- Hot water supply: Tankless water heaters can deliver an unlimited amount of hot water on demand, whereas traditional water heaters have a tank size limit.
- Cost: The initial cost of a tankless water heater can be higher than a traditional one, but the operational cost is usually lower due to its higher energy efficiency. Conversely, traditional water heaters have a lower initial cost but higher operational costs due to lower energy efficiency.
- Risk of water damage: With no storage tank to potentially leak or burst, tankless water heaters pose less risk of water damage compared to traditional water heaters that can leak or burst.
- Environment impact: Due to their higher energy efficiency and less waste, tankless water heaters typically have a lower environmental impact than traditional water heaters.
Energy efficiency: How do tankless water heaters save energy?
Tankless water heaters save energy through their on-demand heating mechanism. Unlike traditional water heaters that constantly heat a large tank of water and maintain it at a set temperature even when not in use, tankless heaters only heat the water when a hot water tap is turned on.
This means they’re not expending energy to keep water hot when it’s not needed. They avoid the energy losses associated with standby heat, which occur in traditional heaters when the stored hot water cools down over time or due to heat loss through the tank walls. This on-demand operation and elimination of standby heat losses make tankless water heaters significantly more energy-efficient.
According to the U.S. Department of Energy, for homes that use 41 gallons or less of hot water daily, tankless water heaters can be 24%–34% more energy-efficient than conventional storage-tank water heaters. For a typical household, this could translate to savings of $100 or more per year, depending on local energy rates.
Cost analysis: Initial investment vs long-term savings with tankless water heaters
- 1. Initial Investment: The upfront cost of a tankless water heater can range from about $500 to $2,000 or more, depending on the model and whether it’s electric or gas-powered. Installation costs can also vary widely, from around $1,000 to $3,000, depending on your home’s existing setup and whether extensive modifications are needed.
- 2. Operational Costs: Monthly operational costs will depend on your local energy rates and your family’s hot water usage. However, because tankless water heaters are more energy-efficient than traditional models, you can expect to save approximately $100 or more per year on your energy bills.
- 3. Maintenance Costs: Regular maintenance, including descaling and part replacements if necessary, can add to the long-term costs of owning a tankless water heater. This might average around $100 to $200 per year, depending on the water hardness in your area and the type of unit you have.
- 4. Replacement Costs: Because tankless water heaters tend to have a longer lifespan—up to 20 years or more compared to 10–15 years for a traditional water heater—you might save on replacement costs in the long run. Considering a new traditional water heater might cost around $500 to $1,000 (not including installation), this could represent significant savings over one or two decades.
How does the size of the house affect the performance of tankless water heaters?
The size of the house can significantly impact the performance of tankless water heaters, as it often determines the demand for hot water. In a small home or apartment with one or two people, a single point-of-use tankless water heater may suffice, providing hot water for a single application at a time, such as a shower or washing machine.
However, in a larger home with multiple bathrooms and appliances that might need hot water simultaneously, a single point-of-use unit may not be sufficient. If multiple people are taking showers, dishes are being washed, and laundry is being done all at the same time, the demand might exceed the heater’s capacity, leading to lukewarm water or inconsistent temperatures.
In this scenario, a whole-house tankless water heater with a higher flow rate or multiple point-of-use units installed at key locations would be required to meet the demand effectively. Therefore, always consider the size of the home and the likely hot water usage when selecting a tankless water heater to maintain optimal performance.
Easy installation and maintenance of tankless water heaters
Installation of tankless water heaters
- Choose the right size and type: Make sure you select a model that suits your hot water needs and available energy source (gas or electric).
- Select the installation spot: Pick an area close to the gas supply line, water line, and electrical source, if needed. Make sure there is proper ventilation.
- Prepare the space: Remove any items that might interfere with the installation. If you’re replacing a traditional water heater, drain and disconnect it first.
- Install the unit: Follow the manufacturer’s instructions to securely mount the unit and connect it to the water line, energy source, and venting system, if applicable. This step is typically best left to a professional due to the complexity and safety requirements involved.
- Test the unit: Turn on a hot water tap and check for proper operation and any leaks.
Maintenance of tankless water heaters
- Regularly descale: Depending on your water hardness, descale the unit once a year or more to prevent mineral buildup that can affect performance.
- Inspect for leaks: Regularly check the unit and its connections for any signs of leaks.
- Clean the air filter: If your unit has an air filter, clean it periodically to promote adequate airflow.
- Schedule professional service: Have a professional inspect and service your unit every few years to ensure it’s operating efficiently and safely. This may include checking the burner, heat exchanger, venting system, and other components.
- Check the temperature setting: Make sure it’s set at a safe and comfortable level, typically around 120 degrees Fahrenheit.
Lifespan and durability: How long do tankless water heaters last?
Tankless water heaters are known for their long lifespan and durability, often outlasting traditional tank-style heaters. With proper maintenance, a tankless water heater can last up to 20 years or more. This is significant when compared to conventional water heaters, which typically have a lifespan of around 10 to 15 years.
The extended lifespan of tankless models can be attributed to their design, which avoids the constant heating and cooling of a large water tank that can lead to wear and tear over time. Many tankless heaters are designed with replaceable parts, allowing you to replace a single component instead of the entire unit, further extending its life. Despite the higher upfront cost, the longer lifespan of tankless water heaters can make them a cost-effective option in the long run.
Environment-friendly aspect of tankless water heaters
First and foremost, their high energy efficiency reduces energy consumption, leading to lower greenhouse gas emissions, especially in models powered by natural gas. By only heating water when it’s needed, tankless heaters avoid the energy waste associated with keeping a full tank of water hot around the clock, as traditional heaters do.
Furthermore, their longer lifespan compared to traditional water heaters means fewer units end up in landfills over time. Many tankless water heaters are designed with replaceable parts, which not only extends their usable life but also reduces waste.
Some models are even made from recyclable materials, further minimizing their environmental impact when they’re eventually replaced.
Potential drawbacks of tankless water heaters: What should you consider?
- Higher upfront cost: Tankless water heaters typically have a higher initial purchase price compared to traditional tank heaters. The installation can also be more complex and costly, especially if modifications are needed to your home’s plumbing, electrical, or venting systems.
- Limited simultaneous usage: While a tankless heater provides hot water on demand, it might struggle to supply enough hot water for multiple simultaneous uses, like taking a shower and running the dishwasher at the same time. In larger households, you may need to install multiple units to meet demand.
- Inconsistent water temperatures: If the demand for hot water exceeds the heater’s capacity, you might experience fluctuations in water temperature.
- Requires regular maintenance: Depending on the hardness of your water, tankless water heaters require regular descaling to maintain their efficiency. Neglecting this maintenance can lead to performance issues over time.
- Potential need for a service upgrade: Some electric tankless water heaters require a lot of power and may necessitate an upgrade to your home’s electrical service. Similarly, gas models might require a larger natural gas line. Both these upgrades can add to the installation cost.
- Not always the best choice for smaller hot water needs: If your household only uses a small amount of hot water, the energy savings might not offset the higher upfront cost of a tankless unit. In some cases, a high-efficiency tank-style heater might be a more cost-effective choice.
Author: Logan
I help people connect with businesses
