Home | Plumbing Guide | Taking Care Of Your Air Conditioning Guide 2021

Heat Pump Water Heater vs Tankless Heater: Which is Better?

Heat Pump Water Heater Vs Tankless Water

Going through the decision between Heat Pump Water Heater vs Tankless Heater remains important for homeowners. The efficiency, performance, and environmental impact of these systems vary, and understanding factors can help make a well-informed choice. Before we compare the two, let’s first understand what they are and how they work.

What is a Heat Pump Water Heater?

A heat pump water heater (HPWH) is a cutting-edge appliance designed to efficiently heat water for residential or commercial use. Unlike traditional water heaters that rely on direct electrical resistance or gas combustion to generate heat, a heat pump water heater operates by leveraging the principles of heat exchange. It extracts warmth from the surrounding air or ground and transfers it to the water, providing an energy-efficient alternative for heating water in various climates.

The key component of a heat pump water heater is, unsurprisingly, the heat pump itself. This pump comprises a refrigerant, a compressor, a condenser, and an evaporator. The process begins with the evaporator absorbing heat from the ambient air or ground, causing the refrigerant to evaporate. The compressor then pressurizes the vaporized refrigerant, raising its temperature. The heated refrigerant passes through the condenser, where it releases the accumulated heat to the water. Finally, the refrigerant returns to its initial state, and the cycle repeats.

It’s important to note that heat pump water heaters come in various configurations, including integrated units that combine the heat pump and storage tank into a single appliance, as well as hybrid systems that can be retrofitted to existing storage tanks. The choice of configuration of water heaters depends on factors such as space availability, installation requirements, and the specific needs of the user.

What is a tankless water heater?

A tankless water heater, also known as an on-demand water heater or instantaneous water heater, is a modern and efficient appliance designed to provide hot water as needed, without the need for a storage tank. Unlike traditional water heaters with a tank that constantly heats and stores a specific volume of water, a tankless water heater heats water on demand, delivering hot water instantaneously when a tap or appliance is turned on.

The basic operation of a tankless water heater involves a heat exchanger, which is the central component responsible for heating the water. When a hot water tap is opened, cold water travels through the heat exchanger. An electric element or a gas burner heats the water as it passes through, raising its temperature to the desired level before being delivered to the faucet or appliance.

Tankless water heaters represent a modern and efficient approach to meeting hot water needs on demand. Their compact design, energy efficiency, and continuous hot water supply make them a popular choice for homeowners looking to optimize space utilization and reduce energy consumption in their households.

Factors to Consider when Comparing Heat Pump Water Heater vs Tankless Heater

1. Energy Efficiency

Heat Pump Water Heater (HPWH)

  • Utilization of Ambient Heat: Extracting heat from the surrounding air, HPWHs capitalize on ambient warmth, ensuring energy efficiency, especially in moderate climates.
  • COP (Coefficient of Performance): With a higher COP compared to traditional electric resistance heaters, HPWHs boast efficient energy conversion, leading to potential long-term cost savings.
  • Reduced Energy Bills: The energy-efficient operation of HPWHs translates into lower monthly bills, making them a financially appealing and environmentally conscious choice.

Tankless Water Heater

  • On-Demand Heating: Tankless heaters offer on-demand hot water, reducing standby heat loss and contributing to overall energy savings.
  • High Thermal Efficiency: Boasting high thermal efficiency, tankless water heaters convert a significant portion of energy input into heat, aligning with sustainability goals.
  • Energy Factor (EF) Ratings: Competitive EF ratings indicate the ability of tankless water heaters to convert energy into hot water effectively, reflecting their commitment to energy efficiency.

2. Performance and Capacity

Heat Pump Water Heater (HPWH)

  • Ambient Temperature Considerations: In colder climates, HPWHs may experience reduced efficiency due to the decreased availability of ambient heat, necessitating careful consideration.
  • Recovery Time: HPWHs might have a longer recovery time, especially in colder climates, impacting the speed at which the unit reheats water after a significant demand.
  • Size and Space Requirements: The bulkier design of HPWHs requires more installation space, a crucial consideration for homeowners with limited utility room space.

Tankless Water Heater

  • Continuous Hot Water: The on-demand heating capability of tankless water heaters ensures a continuous supply of hot water, catering to the needs of larger households with multiple hot water requirements.
  • Flow Rate Considerations: Higher flow rates in tankless water heaters accommodate larger households with simultaneous hot water needs, ensuring consistent performance during peak usage times.
  • Compact Design: The compact design of tankless water heaters allows for flexible installation in smaller spaces, freeing up valuable room compared to bulkier alternatives.

3. Environmental Impact

Heat Pump Water Heater (HPWH)

  • Lower Greenhouse Gas Emissions: HPWHs contribute to environmental sustainability by producing fewer greenhouse gas emissions, aligning with the global push for greener technologies.
  • Reduced Electricity Demand: Operating with reduced electricity demand, HPWHs support eco-friendly practices and contribute to a lower overall environmental impact.
  • Longevity and Maintenance: The longer lifespan of HPWHs minimizes replacements, reducing environmental impact from manufacturing and disposal, and reinforcing their eco-conscious appeal. “Plumbing repair Seattle” may be needed if maintenance is not done regularly.

Tankless Water Heater

  • Reduced Standby Heat Loss: Tankless water heaters, by eliminating standby heat loss, contribute to lower energy consumption and reduced environmental impact, aligning with sustainable living practices.
  • Energy Savings: The energy-efficient nature of tankless water heaters directly translates into reduced reliance on fossil fuels, promoting energy conservation and environmental responsibility.
  • Recyclability: Designed with recyclable materials, tankless water heaters facilitate environmentally responsible disposal practices, supporting a circular economy.
Heat Pump Water Heater Vs Tankless Water

4. Installation and Costs

Heat Pump Water Heater (HPWH)

  • Initial Cost: While HPWHs have a higher upfront cost, potential incentives, and rebates, coupled with long-term energy savings, can justify the initial investment.
  • Installation Complexity: Heat pump installation might be more complex, requiring careful consideration of the home’s infrastructure and potential modifications for optimal performance.
  • Incentives and Rebates: Exploring available programs for HPWH incentives and rebates can significantly reduce the overall cost, making them a more economical choice.

 Tankless Water Heater

  • Initial Cost: Tankless heaters, while having a higher initial cost compared to traditional heaters, are often more affordable than HPWHs, with potential energy savings providing a compelling financial case.
  • Installation Flexibility: Tankless water heater electric installation is flexible, especially in homes with limited space, potentially resulting in lower installation costs.
  • Energy Savings and ROI: The long-term energy savings associated with tankless water heaters contribute to a favorable return on investment, making them financially attractive over the unit’s lifespan.

5. Maintenance and Lifespan

Heat Pump Water Heater (HPWH)

  • Regular Maintenance: HPWHs may require regular maintenance, including filter cleaning and refrigerant level checks. Homeowners must factor in maintenance efforts to ensure optimal performance. With a longer lifespan, often exceeding 15 years, HPWHs contribute to fewer replacements.
  • Warranty Considerations: Understanding the warranty terms is crucial, providing homeowners with financial protection and peace of mind in case of unexpected issues.

Tankless Water Heater

  • Minimal Maintenance for tankless water heaters: They typically require less maintenance, with simple flushing to remove mineral deposits. This ease of maintenance enhances their appeal to homeowners seeking convenience.
  • Lifespan: The extended lifespan of tankless heaters, around 20 years or more, contributes to long-term cost savings and a reduced environmental footprint, reinforcing their durability.
  • Warranty Coverage: Checking the warranty terms before purchase is advisable, ensuring homeowners are protected against potential malfunctions or defects throughout the unit’s lifespan.

6. Integration with Renewable Energy Sources

Heat Pump Water Heater (HPWH)

  • Compatibility with Solar Panels: HPWHs, in some instances, can be integrated with solar panels, harnessing renewable energy to further enhance their environmental credentials. This synergy promotes a holistic approach to sustainable water heating.
  • Dual-Mode Operation: Some HPWH models offer dual-mode operation, allowing users to switch between electric and solar modes. This flexibility enables homeowners to optimize energy usage based on weather conditions and the availability of sunlight.
  • Reduced Grid Dependency: The ability of HPWHs to tap into renewable energy sources contributes to reduced dependency on the electrical grid, fostering self-sufficiency and resilience against energy fluctuations.

Tankless Water Heater

  • Compatibility with Solar Preheating: Certain tankless water heaters can be integrated with solar preheating systems. This collaborative approach utilizes solar energy to preheat water before it enters the tankless unit, reducing the energy required for the final temperature adjustment.
  • Hybrid Systems: Hybrid tankless water heaters may combine traditional heating methods with solar or other renewable sources. This combination optimizes energy efficiency, allowing users to harness green energy when available.
  • Environmental Footprint: Assessing the overall environmental impact involves considering the integration of renewable energy sources, as tankless water heaters can contribute to sustainability by reducing reliance on conventional energy.

7. Water Quality and Softening Requirements

Heat Pump Water Heater (HPWH)

  • Impact on Water Hardness: HPWHs are generally less affected by water hardness compared to traditional tank-style heaters. Understanding the water quality in a specific location is crucial, as excessive hardness can affect the efficiency and lifespan of heating elements.
  • Compatibility with Water Softeners: HPWHs may require water softeners in areas with hard water to prevent mineral buildup within the system. The compatibility with water-softening solutions should be considered in regions with challenging water conditions.
  • Maintenance Considerations: Regular maintenance, including descaling and monitoring water quality, is essential for optimal HPWH performance. Understanding the water quality requirements ensures prolonged efficiency.

Tankless Water Heater

  • Water Hardness Impact: Tankless heaters can be more sensitive to water hardness, potentially requiring water softeners to prevent and remove scale buildup. The impact of water quality on the unit’s components should be factored into the decision-making process.
  • Compatibility with Water Treatment Systems: Certain tankless water heaters may have specific requirements regarding water quality and treatment. Compatibility with water treatment systems, such as water softeners, should be assessed for long-term performance.
  • Maintenance and Scale Prevention: Regular maintenance, including descaling procedures, is crucial for tankless water heaters in hard water areas. Exploring options for scale prevention and addressing water quality concerns is integral to maintaining efficiency.

8. Noise Levels During Operation

Heat Pump Water Heater (HPWH)

  • Decibel Ratings: HPWHs generally operate with lower noise levels compared to traditional water heaters. Understanding the decibel ratings of different models aids in selecting units that align with acceptable noise thresholds, especially in residential settings.
  • Location Considerations: The placement of HPWHs in living spaces is vital. Being quieter during operation, HPWHs provide more flexibility in terms of installation locations without causing disruptions to daily activities. It’s best to consult with plumbers in Seattle to assess the best location for your water heater.
  • Fan Noise Variability: HPWHs utilize fans to move air through the system. Assessing the variability of fan noise, particularly during colder seasons when the unit extracts heat from the ambient air, ensures a comfortable living environment.

Tankless Water Heater

  • Noise Levels During Ignition: Tankless heaters may produce a brief sound during ignition, typically caused by the gas burner or electric elements. Understanding the noise characteristics during startup helps set realistic expectations for users.
  • Continuous Operation Sound: While tankless water heaters are generally quiet during operation, some models may produce a consistent sound as water flows through the system. Evaluating the noise levels during continuous use ensures compatibility with individual preferences.
  • Soundproofing Considerations: Depending on the location of the water heater, considering soundproofing measures, such as insulating the installation space or choosing units with lower noise output, contributes to a more harmonious living environment.

9. Technology Integration and Smart Features

Heat Pump Water Heater (HPWH)

  • Smart Thermostats and Connectivity: Some advanced HPWH models come equipped with smart thermostats and connectivity features. These technologies allow users to remotely control and monitor the water heater, optimizing energy usage based on usage patterns and preferences.
  • Adaptive Learning Algorithms: Certain HPWHs employ adaptive learning algorithms that analyze usage patterns over time. The system then adjusts heating cycles and operation to optimize efficiency, providing a more personalized and energy-efficient experience.
  • Integration with Home Automation Systems: Evaluating compatibility with home automation systems ensures seamless integration of the HPWH into a smart home environment, enhancing user convenience and control.

Tankless Water Heater

  • Digital Controls and User Interfaces: Many tankless water heaters feature digital controls and user-friendly interfaces. Evaluating the accessibility and functionality of these controls ensures a user-friendly experience and the ability to customize settings.
  • Remote Control and Monitoring: Some tankless water heaters offer remote control and monitoring capabilities through mobile apps. This feature allows users to adjust settings and monitor energy usage from their smartphones, enhancing convenience.
  • Compatibility with Smart Home Platforms: Assessing compatibility with popular smart home platforms enables seamless integration with existing smart home ecosystems. This integration streamlines control and monitoring processes, contributing to a connected home experience.

10. Cold Water Sandwich Effect

Heat Pump Water Heater (HPWH)

  • Minimization of Cold Water Sandwich: The cold water sandwich effect, where a brief burst of cold water occurs between hot water usage cycles, can be minimized in some HPWH models. Understanding the mitigation measures implemented in the unit ensures a more consistent hot water supply.
  • Dual Heating Elements or Compressors: HPWHs with dual heating elements or compressors may effectively address the cold water sandwich effect by ensuring a continuous and even supply of hot water during usage cycles.
  • User Feedback and Reviews: Exploring user feedback and reviews specific to the cold water sandwich effect for different HPWH models provides valuable insights into real-world performance and user satisfaction.

Tankless Water Heater

  • Frequency and Severity: The cold water sandwich effect may vary in frequency and severity among tankless water heaters. Evaluating user experiences and product specifications helps in understanding how different units handle this phenomenon.
  • Technological Solutions: Some tankless heaters incorporate specific technologies, such as buffer tanks or recirculation systems, to mitigate the cold water sandwich effect. Understanding the technological solutions employed contributes to informed decision-making.
  • Installation Considerations: Proper installation, including the positioning of the tankless water heater and any additional components to address the cold water sandwich effect, is crucial. Consulting with expert plumbers in Seattle ensures optimal performance and user satisfaction.


In searching heat pump water heater vs tankless heater, consider a comprehensive set of factors and professional help from Einstein Pros as essential. Heat pump and tankless water heaters both have their defining characteristics, hence choosing one that matches your needs is important for comfort and efficiency. By delving into these considerations, homeowners can make well-informed choices to choose which heating solution to install.

Schedule an Estimate

Please fill up this form to send us your message, questions, comments, suggestions, and feedback. We will get back to you as soon as possible. Thank You!