Upgrading your water heater can significantly improve your home's energy efficiency and comfort. Choosing between an electric or gas tankless water heater is an important decision, particularly with new regulations such as California's ban on gas-powered water heaters.
Both types offer numerous benefits compared to traditional storage tank heaters. However, they differ in key aspects like heating mechanisms, costs, efficiency, and water flow rates. In this guide, we'll break down the differences to help you determine which option is best suited for your home.
Key Differences Between Electric and Gas Tankless Water Heaters
- Heating Source
- Electric Tankless Water Heaters: Use electricity to power heating elements that heat water on demand.
- Gas Tankless Water Heaters: Use natural gas or propane to ignite burners that heat the water through combustion.
- Efficiency
- Electric: Highly efficient with UEF (Uniform Energy Factor) ratings of 0.96 or higher.
- Gas: Typically less efficient with UEF ratings between 0.81 and 0.96.
- Flow Rate
- Electric: Lower flow rates, generally between 2 to 5 gallons per minute (GPM).
- Gas: Higher flow rates, often exceeding 5 GPM, ideal for larger households.
- Cost
- Electric: Lower upfront cost and easier installation. This makes them a budget-friendly option for smaller homes.
- Gas: Higher installation costs due to the need for ventilation and gas lines, but better suited for homes with higher water demands.
How Do Electric and Gas Tankless Water Heaters Heat Water?
Electric Tankless Water Heaters
Electric tankless water heaters use metal heating elements that are activated by electricity when hot water is needed. These elements heat water instantaneously as it flows through the unit. It provides an uninterrupted hot water supply. The absence of a storage tank means less energy is wasted keeping water hot when it's not needed.
Gas Tankless Water Heaters
Gas models heat water through combustion. When the unit detects water flow, it opens a gas valve that allows natural gas or propane to ignite a burner. The heat from the burner is transferred to a heat exchanger. This warms the water as it passes through. Gas units are ideal for homes with high water demand since they generally have faster recovery times and higher flow rates.
Cost Comparison: Electric vs. Gas Tankless Water Heaters
Initial costs for both types of tankless water heaters vary based on the unit and installation needs.
The cost of electric tankless water heaters without installation typically ranges from $400 to $2,500. When factoring in installation, the total cost can increase to between $1,800 and $7,200. This depends on the model and any required electrical upgrades.
In comparison, gas tankless water heaters are generally more expensive. Without installation, they range from $1,200 to $2,900. The total cost with installation can be significantly higher. It falls between $4,800 and $8,500, due to the need for venting and gas line work. Thus, while electric models offer lower upfront costs, gas models tend to be more expensive overall, especially when installation is included.
Electric units tend to have a lower upfront cost and are cheaper to install since they don’t require venting or gas line connections. While more expensive to install, gas tankless heaters provide better water flow rates and can meet higher water demands, especially for larger homes.
Efficiency Comparison
When comparing efficiency, electric tankless water heaters generally outperform gas models. Most electric units boast a UEF rating of 0.96 or higher. This means they convert nearly all the energy they use into heating water. This efficiency helps reduce overall energy consumption and utility costs, particularly in areas where electricity rates are low.
On the other hand, gas models tend to have slightly lower UEF ratings. They range from 0.81 to 0.96. However, they are still far more efficient than traditional storage tank heaters. Gas units are also a better fit for regions where natural gas is inexpensive, as this can offset the slightly lower efficiency rating.
Electric tankless water heaters typically have a higher efficiency rating, with a UEF (Uniform Energy Factor) of 0.96 or higher. This makes them not only more energy-efficient but also more environmentally friendly. They produce lower greenhouse gas emissions compared to gas models.
In contrast, gas tankless water heaters have a slightly lower efficiency rating, usually between 0.81 and 0.96 UEF. While still efficient, they tend to produce more emissions due to the combustion process. It makes them less eco-friendly than their electric counterparts.
Water Flow Rates
Gas tankless water heaters generally offer higher water flow rates compared to electric models. They are a better option for larger homes or households with multiple bathrooms. A gas tankless water heater can typically provide between 5 and 10+ GPM. This allows for several showers, dishwashers, and washing machines to run simultaneously without a drop in water temperature.
Electric models typically provide between 2 and 5 GPM. While this may be sufficient for smaller households or homes with lower water usage, it may not meet the demands of larger families with multiple hot water needs at once.
Determining Your Water Flow Needs
To decide which type of tankless water heater is right for your home, consider your household's hot water usage. For example:
- A single shower typically requires 2 GPM.
- A dishwasher uses about 1.5 GPM.
- A washing machine needs about 2 GPM.
If you expect to run multiple appliances or showers at the same time, a higher GPM rating (5+ GPM) would be necessary, making a gas tankless water heater a better fit.
Installation Considerations
Electric Tankless Water Heater Installation
Electric tankless water heaters are generally easier and less expensive to install. They don't require venting, which means they can be installed in smaller spaces such as closets or utility rooms. The only potential drawback is that they may require an electrical upgrade to handle the unit's power demands, especially for larger models.
Gas Tankless Water Heater Installation
Gas tankless water heaters require more complex installation due to the need for proper venting and gas line hookups. These units must be vented outside to release the byproducts of combustion. This may involve additional installation costs. It’s important to have a licensed professional handle the installation to maintain safety and compliance with local building codes.
When it comes to installation, electric tankless water heaters are generally easier and less expensive to set up because they don’t require venting. This flexibility allows them to be installed in tighter spaces like closets or utility rooms. However, larger models might need an electrical system upgrade to handle their power requirements.
Gas tankless water heaters require more complex installations due to the need for venting and proper gas line hookups. These units must be vented to the outside to safely release combustion byproducts, which can increase installation costs.
Additionally, gas models usually need more installation space compared to electric units. They are less versatile in terms of placement. Therefore, while electric units offer lower installation costs and greater flexibility, gas units often involve higher costs due to the additional requirements for gas lines and ventilation.
Both systems have their advantages depending on your specific installation needs and available space.
Maintenance and Longevity
Maintenance Requirements
Electric tankless water heaters typically require less maintenance than gas units. Since they don’t have any combustion components, there’s no need to worry about venting systems or gas lines. Routine maintenance for electric models mainly involves descaling the unit to prevent mineral buildup.
On the other hand, gas tankless water heaters need more frequent maintenance to keep the gas burners and venting system in good working condition. Regular inspections by a professional are recommended to maintain safe operation and efficiency.
Expected Lifespan
Both electric and gas tankless water heaters are known for their longevity with an average lifespan of 15 to 20 years. This is significantly longer than traditional storage tank water heaters.
Environmental Impact
Electric tankless water heaters are often considered the more environmentally friendly option due to their lower greenhouse gas emissions. Because they don’t rely on combustion, they don’t produce harmful emissions like carbon dioxide. In areas where renewable energy sources power the electric grid, using an electric tankless water heater can greatly reduce your home’s carbon footprint.
Gas models still produce some greenhouse gases during the combustion process. If reducing your environmental impact is a priority, an electric model may be the better choice.
Choosing the Right Tankless Water Heater
When deciding between an electric or gas tankless water heater, consider the following factors:
- Household Size and Water Demand: Larger households with high hot water demands may benefit more from a gas tankless water heater due to its higher flow rate.
- Installation Budget: If you’re looking for a more affordable and simpler installation, an electric tankless water heater is likely the better option.
- Energy Efficiency Goals: Electric models offer superior energy efficiency and are more environmentally friendly.
- Local Energy Costs: In areas with low gas prices, a gas tankless water heater may offer long-term savings despite the higher upfront cost.
Both electric and gas tankless water heaters offer significant advantages over traditional storage tank systems, but the right choice depends on your specific needs. If you’re looking for a high-efficiency, environmentally friendly option, an electric tankless water heater may be ideal, especially for smaller homes.
On the other hand, if you have a larger household with high hot water demand, a gas tankless water heater offers superior water flow rates and may be more suitable for your needs.
Consult with a professional installer to assess your home’s hot water requirements, budget, and local energy costs. Whether you choose gas or electric, upgrading to a tankless water heater will provide you with energy savings, reliability, and endless hot water for years to come.
Need help choosing? Contact our team at Water Heaters Now for expert advice and installation services. We'll help you find the perfect tankless water heater to meet your home’s needs.
