Gas vs Electric Tankless Water Heater

Tired of running out of hot water just when you need it most? Sick of paying sky-high energy bills for heating water? If you’re ready to ditch your old water heater and upgrade to a tankless one, you’ve come to the right place. But which is better: gas or electric?

In this post, we’ll break down the pros and cons of each type, so you can choose the perfect tankless water heater for your home. We’ll talk about costs, energy efficiency, and which one might be best for your family’s needs. Let’s get started!

Gas vs Electric Tankless Water Heater – The Difference

What Are Tankless Water Heaters?

Tankless water heaters, often called on-demand water heaters, provide hot water only as it is needed. Unlike traditional water heaters that continuously heat and reheat water to keep it at a set temperature, tankless units heat water directly without the use of a storage tank. This method can lead to energy savings and provides a constant supply of hot water, which is a major selling point for these systems.

How Do Tankless Water Heaters Work?

• Electric Tankless Water Heaters: These heaters use electric elements to heat water as it passes through the unit. They are generally easier to install, requiring only an electrical connection and adequate amperage.
• Gas Tankless Water Heaters: These units use a gas burner to heat water on-demand. They require venting to the outdoors and typically have higher flow rates than electric models.

Key Takeaways:

• Tankless water heaters provide hot water on-demand without storing it in a tank, offering continuous supply and energy efficiency.
• Electric models are easier to install but generally have lower flow rates, while gas models require venting but provide higher flow rates.

Detailed Energy Efficiency Comparison

Understanding Efficiency Ratings

Energy efficiency is a critical factor in evaluating tankless water heaters. Here’s a more detailed comparison:

• Electric Tankless Water Heaters: These units are extremely efficient because they directly convert electricity into heat with minimal loss, boasting Energy Factor (EF) ratings close to 1.00. For instance, a typical model by a leading brand might exhibit an EF rating of 0.99, which implies that 99% of the electrical energy is converted into heat energy for water heating.
• Gas Tankless Water Heaters: Gas models are slightly less efficient due to the energy lost in the form of exhaust gases. However, advancements such as condensing technology have improved their efficiency. A high-end gas tankless water heater might have an EF rating of up to 0.95, which is close to that of electric models but still involves some energy loss.

Calculating Energy Consumption And Savings

To illustrate, consider a household that uses 41 gallons of hot water daily. An electric tankless water heater with an EF of 0.99 and a daily electricity usage of 12 kWh would result in an annual operation cost of approximately $200, based on the average electricity price of $0.13 per kWh.

In contrast, a gas tankless water heater with an EF of 0.95, consuming 160 therms per year, would cost about $160 annually, assuming a gas price of $1 per therm. These figures highlight the potential savings gas models can offer despite their lower efficiency, particularly in areas with lower gas prices.

Key Takeaways:

• Electric tankless water heaters are highly efficient with EF ratings near 1.00, making them nearly 100% efficient at converting electricity to heat.
• Gas tankless water heaters, with recent technology improvements, can achieve EF ratings up to 0.95, offering a competitive option especially in regions with lower natural gas costs.

Installation Complexity And Cost Analysis

Detailed Installation Requirements

The installation process for each type of tankless water heater involves specific requirements that can affect the overall ease and cost:

• Electric Tankless Water Heaters: Installation typically requires upgrading the home’s electrical system to accommodate the high power demand, often necessitating an upgrade to a 200-amp service. This might include additional circuit breakers and dedicated lines. Installation costs can range from $800 to $1,500, not including potential major electrical upgrades.
• Gas Tankless Water Heaters: These units require a gas line and proper venting, which can significantly increase installation complexity and cost. The need for stainless steel venting systems and potentially extending or upgrading gas lines can bring installation costs to between $1,200 and $2,000. Moreover, ensuring proper ventilation to safely remove combustion gases adds to the complexity.

Long-term Cost Implications

Beyond the initial installation, the long-term costs associated with each type of heater also differ significantly. Electric units, while more expensive in terms of energy consumption in regions with high electricity prices, have lower maintenance costs. Gas units, though cheaper to operate monthly, may incur higher maintenance and service costs due to the complexity of their components and the need for regular safety checks.

Key Takeaways:

• Electric tankless water heaters require significant electrical upgrades, which can be costly, but are simpler in terms of physical installation.
• Gas tankless water heaters, while more expensive to install due to venting and gas line requirements, can offer lower operational costs in areas with inexpensive gas.

Performance Metrics And Longevity

Assessing Flow Rates And Heating Capabilities

The performance of tankless water heaters is often gauged by their flow rates, which indicate how much hot water they can deliver at a given time, measured in gallons per minute (GPM).

• Electric Tankless Water Heaters: These typically offer flow rates ranging from 1.5 to 8 GPM. For instance, a standard electric model might deliver 3.5 GPM sufficient to simultaneously supply hot water to a shower and a sink. However, their performance can be limited in colder climates where the incoming water temperature is low, requiring the unit to work harder to heat the water.
• Gas Tankless Water Heaters: Gas models generally provide higher flow rates, from 5 to 10+ GPM, due to the rapid heating capability of gas burners. A high-performance gas tankless model can comfortably supply more than one major application at once, like running two showers and a dishwasher simultaneously without a drop in temperature.

Longevity And Maintenance Insights

Both electric and gas tankless water heaters have a significantly longer lifespan compared to traditional tank heaters, typically ranging from 20 to 30 years. This longevity is influenced by maintenance, water quality, and usage patterns.

• Electric Tankless Water Heaters: These units are less prone to wear and tear because they have no moving parts and do not involve combustion, making them relatively maintenance-free apart from periodic cleaning of the inlet screen and checking electrical components for safety.
• Gas Tankless Water Heaters: These require more regular maintenance, including annual checks of the burner, heat exchanger, and venting system to ensure they are free from blockages and operating efficiently. Additionally, components such as the gas valve and ignition system need periodic inspections to prevent failures.

Comparative Durability

The durability of a tankless water heater is also a factor of its construction and the quality of its components. For example, models with stainless steel or copper heat exchangers are typically more durable and resistant to corrosion and scale buildup compared to those with cheaper materials.

Key Takeaways:

• Electric tankless heaters are ideal for smaller households or moderate climates and require minimal maintenance, focusing on electrical safety and cleanliness.
• Gas tankless heaters, suitable for larger homes or colder areas, offer high flow rates and require more comprehensive maintenance to ensure longevity and performance.

Environmental Impact And Sustainability Considerations

Carbon Emissions And Environmental Footprint

The choice between gas and electric tankless water heaters significantly affects your home’s carbon footprint due to differences in how these units are powered.

• Electric Tankless Water Heaters: The environmental impact largely depends on the source of the electricity. If your electricity is generated from renewable sources like solar, wind, or hydroelectric power, the environmental impact is minimal. However, if it relies on coal or natural gas, the carbon footprint could be substantial. On average, electric heaters have a lower emissions profile when connected to a grid that utilizes a significant proportion of renewable energy.
• Gas Tankless Water Heaters: These heaters emit carbon dioxide and other greenhouse gases as a byproduct of burning natural gas. Although more efficient than traditional tank models due to their on-demand functionality, they still contribute to air pollution and global warming. Advances like low-NOx (nitrogen oxide) burners help reduce emissions, but the inherent issue of burning fossil fuels remains.

Energy Source Sustainability

Analyzing the sustainability of the energy sources for water heaters is crucial for making an environmentally conscious decision.

• Electric Tankless Water Heaters: As the shift towards renewable energy sources continues globally, electric tankless heaters potentially become more sustainable over time. They are already preferable in regions heavily investing in green energy infrastructures, like parts of Europe and the United States.
• Gas Tankless Water Heaters: The sustainability of gas heaters is less promising in the long term as they depend on finite natural gas resources, which are subject to volatile markets and geopolitical influences. However, innovations in biogas and synthetic natural gas could potentially offset some of the sustainability concerns.

Impact On Water Conservation

Both electric and gas tankless water heaters contribute positively to water conservation. By providing hot water on demand, they eliminate the need for storing water in tanks, reducing standby losses and lessening the incidence of excess water being heated and not used.

Key Takeaways:

• Electric tankless water heaters offer a cleaner, potentially more sustainable solution, especially when paired with a renewable energy-powered grid.
• Gas tankless heaters, while efficient in their category, still rely on burning fossil fuels, which poses challenges for long-term sustainability despite advances in emission reduction technologies.

Suitability For Different Home Sizes And Layouts

Adaptability To Various Living Spaces

The choice between gas and electric tankless water heaters often hinges on the specific needs and constraints of different home sizes and layouts. Here’s a deeper look:

• Electric Tankless Water Heaters: These units are compact and do not require venting, making them highly adaptable for smaller homes, apartments, or areas with limited space such as utility closets. They can be installed in a variety of locations within a home due to their size and lack of combustion-based operational requirements. However, their effectiveness may diminish in larger homes where multiple simultaneous demands for hot water can exceed the heater’s capacity.
• Gas Tankless Water Heaters: Gas models are generally better suited for larger homes with multiple bathrooms. They can handle higher demands for hot water across several points of use simultaneously without significant drops in temperature. The need for venting and larger space for installation makes them less suitable for very compact areas or homes without existing gas lines.

Considerations For Retrofitting

Retrofitting a tankless water heater in an existing home can also vary in complexity based on the type:

• Electric Tankless Water Heaters: Retrofitting an electric model is typically easier, requiring only adequate electrical support. Homes may need an upgrade in their electrical panel to handle the high power demand, but no major structural changes are necessary.
• Gas Tankless Water Heaters: Installing a gas unit in an existing setup often involves more extensive modifications. This includes installing new gas lines and venting systems, which can be invasive and costly, particularly if the home did not previously accommodate gas appliances.

Climate And Water Temperature Considerations

The efficiency of tankless water heaters can also be influenced by regional climate conditions:

• Electric Tankless Water Heaters: In colder regions, the incoming water temperature can be quite low, demanding more from the heater to reach the desired temperature. This might require a more robust electric system or multiple units to maintain efficiency.
• Gas Tankless Water Heaters: Gas heaters generally perform better in cold climates due to their higher capacity and quicker heat-up times. They can raise the water temperature more effectively across a wider range of incoming temperatures.

Key Takeaways:

• Electric tankless heaters are ideal for smaller spaces or homes needing simple installation without major modifications.
• Gas tankless heaters are more appropriate for larger homes or colder climates where high demand and quick heat-up are necessary.

Reliability And Safety Features

Evaluating Reliability Factors

When choosing a tankless water heater, reliability is a crucial aspect. Here’s how both types measure up:

• Electric Tankless Water Heaters: These are generally considered highly reliable due to their simple design, which includes fewer moving parts and no requirements for combustion-related components. They are less susceptible to issues that can affect gas heaters, such as venting problems or gas leaks. The primary concerns usually revolve around electrical connections and the longevity of heating elements, which are typically designed for extensive use.
• Gas Tankless Water Heaters: While these units are also designed for long-term reliability, they involve more complex systems including burners, heat exchangers, and exhaust flues. Regular maintenance is crucial to avoid common issues like burner clogs and vent blockages, which can impact performance and safety.

Safety Features And Considerations

Both electric and gas tankless water heaters incorporate a range of safety features, but their focus areas differ due to the nature of their operation:

• Electric Tankless Water Heaters: These units often include built-in electrical safety features such as ground-fault circuit interrupters (GFCIs) and thermal cut-outs to prevent overheating and electrical hazards. They are inherently safer in environments where ventilation is a concern, as they do not emit gases.
• Gas Tankless Water Heaters: Safety features in gas models are more focused on preventing combustion-related issues. These include oxygen depletion sensors, flame failure devices, and exhaust fan monitors to ensure that combustion is efficient and safe. Regular inspections are vital to maintain these safety mechanisms.

Maintenance Requirements For Optimal Performance

Maintaining a tankless water heater is key to ensuring both safety and reliability:

• Electric Tankless Water Heaters: Maintenance is relatively straightforward, typically involving cleaning mineral deposits from components and checking the integrity of electrical connections. Many models facilitate easy access to filters and heating elements for user servicing.
• Gas Tankless Water Heaters: These require more intensive maintenance due to their complex components. Annual inspections by qualified technicians are recommended to check the venting system, clean the burner assembly, and test the unit’s safety controls. This not only ensures efficient operation but also prevents safety hazards related to gas and combustion.

Key Takeaways:

• Electric tankless heaters offer greater simplicity and reduced safety concerns, making them reliable and easier to maintain.
• Gas tankless heaters, while capable of handling higher demands, require more rigorous maintenance and have stringent safety requirements due to the risks associated with gas combustion.

Also Check:

• Gas Water Heater Venting Options
• How Long Does It Take For Hot Water To Come Back
• 8 Best Under Sink Water Heater Reviews
• 6 Best Direct Vent Water Heater

FAQs:

Conclusion

Choosing between gas and electric tankless water heaters is crucial. It impacts your comfort and long-term expenses. Consider energy efficiency, cost, and performance. There’s a tankless water heater that fits your needs. Evaluating these factors can enhance your home’s efficiency and help achieve your environmental goals.