A hot water boiler tankless heater, also known as an on-demand water heater, is a highly efficient and modern alternative to traditional tank water heaters. These innovative systems provide a continuous supply of hot water, while offering significant energy savings and a smaller footprint compared to their conventional counterparts.
How Does a Tankless Water Heater Work?
The core principle behind a tankless water heater is to heat water only when it is needed, rather than maintaining a constant supply of hot water in a storage tank. When a hot water tap is turned on, cold water is drawn into the tankless heater through a dedicated pipe connected to the plumbing system. Inside the heater, either a gas burner or an electric element rapidly heats the water to the desired temperature as it flows through the system. Once the hot water tap is turned off, the tankless heater immediately stops heating the water, eliminating standby heat loss and wasted energy.
Benefits of a Tankless Water Heater Over a Traditional Tank Water Heater
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Energy Efficiency: Tankless water heaters are significantly more energy-efficient than traditional tank water heaters. By only heating water on demand, they eliminate the standby heat loss associated with maintaining a constant supply of hot water in a storage tank. This can result in energy savings of up to 34% for gas-fired tankless heaters and up to 14% for electric tankless heaters, according to the U.S. Department of Energy.
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Endless Hot Water: Tankless water heaters provide a continuous supply of hot water, eliminating the need to wait for a large storage tank to refill. The flow rate of a tankless heater typically ranges from 2 to 10 gallons per minute (GPM), allowing multiple fixtures to be used simultaneously without running out of hot water.
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Space-Saving: Tankless water heaters are generally much smaller and more compact than traditional tank water heaters, making them an ideal choice for homes with limited space. The average tankless heater is about the size of a carry-on suitcase, compared to the bulky storage tanks that can take up significant floor space.
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Longer Lifespan: Tankless water heaters have a significantly longer lifespan than traditional tank water heaters. While tank heaters typically last 8 to 12 years, tankless models can often operate for 20 years or more with proper maintenance.
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Environmental Benefits: By reducing energy consumption and eliminating standby heat loss, tankless water heaters are a more environmentally friendly option. They contribute to lower greenhouse gas emissions and a smaller carbon footprint compared to traditional tank water heaters.
Technical Specifications of Tankless Water Heaters
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Flow Rate: The flow rate of a tankless water heater determines the maximum amount of hot water it can produce at a given time. Typical flow rates range from 2 to 10 GPM, with higher-end models capable of up to 12 GPM. The required flow rate will depend on the size of your household and the number of fixtures that may be used simultaneously.
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Temperature Rise: The temperature rise of a tankless water heater indicates how much it can increase the temperature of the incoming cold water. Typical temperature rises range from 30°F to 70°F, with higher-end models capable of up to 90°F temperature rise. This is an important consideration, as the incoming water temperature can vary significantly based on your geographic location and the time of year.
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Energy Efficiency Ratings: When selecting a tankless water heater, look for models with high energy efficiency ratings, such as ENERGY STAR certification. These ratings indicate the heater’s ability to convert fuel or electricity into usable hot water, with higher-rated models offering greater energy savings.
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Gas or Electric: Tankless water heaters can be powered by either natural gas, propane, or electricity. Gas-fired models are generally more energy-efficient, with typical energy factor (EF) ratings ranging from 0.82 to 0.98. Electric tankless heaters have EF ratings typically between 0.97 and 0.99, but may have higher operating costs depending on your local utility rates.
DIY Considerations for Installing a Tankless Water Heater
When considering a DIY installation of a tankless water heater, there are several important factors to keep in mind:
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Proper Sizing: Accurately determining the appropriate size of the tankless water heater for your household’s hot water demand is crucial. Factors such as the number of bathrooms, the number of occupants, and the expected simultaneous usage of hot water fixtures should all be taken into account. Oversizing or undersizing the heater can lead to inefficient operation and suboptimal performance.
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Venting and Plumbing Requirements: Tankless water heaters have specific venting and plumbing requirements that must be met to ensure safe and proper operation. This may involve installing dedicated gas lines, upgrading electrical service, and ensuring proper drainage and condensate management.
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Maintenance and Cleaning: Regularly cleaning the internal components of a tankless water heater is essential to prevent sediment and mineral buildup, which can reduce efficiency and lifespan. Manufacturers typically recommend annual maintenance, including flushing the system and inspecting critical components.
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Professional Installation: While some DIY-inclined homeowners may feel comfortable tackling the installation of a tankless water heater, it is generally recommended to hire a licensed and experienced plumber or HVAC technician. They can ensure the proper sizing, installation, and integration of the tankless heater with your home’s existing plumbing and electrical systems.
References
- U.S. Department of Energy – Tankless or Demand-Type Water Heaters: https://www.energy.gov/energysaver/water-heating/tankless-or-demand-type-water-heaters
- ENERGY STAR – Certified Water Heaters: https://www.energystar.gov/products/water_heaters
- Stiebel Eltron USA – Tankless Water Heater: https://www.stiebel-eltron-usa.com
- Navien – High-Efficiency Hot Water & Heating Solutions: https://www.navieninc.com
- Eccotemp – Best Gas Tankless Water Heaters: https://www.eccotemp.com/gas-tankless/