Tankless water heaters first became commercially available in the late 1920s when Stiebel-Eltron introduced them. Compared to conventional tank water heaters, tankless water heaters are more compact and energy-efficient. They operate on-demand, meaning that they only heat water when needed. This is done by passing water through a burner, heating it, and sending it directly to your faucet or shower.
How Do Tankless Water Heaters Work?
As the name suggests, tankless water heaters do not have a “tank” to store water. What they do is heat the water only when it is needed. They instantly start generating hot water at the temperature you set when you turn any hot water lines on. The cold water passes through your water heater’s gas or electric burner and warms the water instantly, which is then delivered directly to your tap or tub.
Tankless water heaters are powered either by gas or electricity. You can choose between natural gas or liquid propane gas for gas models. When it comes to electric ones, they usually require a minimum number of amps to operate. Overall, tankless water heaters are more energy-efficient and save you money in the long run compared to the cost of more conventional tank water heaters.
What are the Top Brands of Tankless Water Heaters?
As a pioneer in tankless water heaters, Stiebel-Eltron is still one of the most reliable brands in the industry, along with Rheem, Rinnai, and Eco-Smart, to name a few.
What’s the Price Range of Tankless Water Heaters?
When it comes down to the pricing, a few different factors affect the overall cost, like the number of gallons of water they heat per minute (usually labeled as MPG), fuel source, and brand. In general, you should expect to pay around $400 to $600 on the low end and about $1,500 to $2,000 on the high end. Keep in mind that it’s recommended for water heaters, including tankless ones, be professionally installed, which increases the overall price.
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What to Look For in a Tankless Water Heater
If you are in the market for a tankless water heater, either because you want to update your existing tank water heater or because you are looking for a more energy-efficient product, these are vital points to keep in mind:
- Fuel Source: If you are replacing your water heater, make sure that the tankless water heater you choose will be compatible with the existing fuel. If you have a tank water heater, you will also need to convert your plumbing system and potentially add a vent as well. When choosing an electric tankless water heater, make sure to check the number of amps needed to operate it and double-check if you have space to add a designated breaker to your circuit box, which is required for most units.
- Energy Efficiency: Several models offer a greater energy efficiency than other tankless units. With some units, you may even qualify to get a rebate from the government.
- Price: This might be a crucial point. Although you can get a tankless water heater for around $500, you will need to consider the installation fee, which may be about $1,000. So when choosing a tankless water heater, always add the installation cost to the overall price tag.
- Usage: Depending on how much hot water you use and how often you use it, you want to have a water heater that meets the demand. Technically, you will never run “out of hot water” since it is generated on demand, but these devices can only heat a limited amount per minute — around 2 to 11 GPM, depending on the model you choose. Check the manufacturer’s location chart, which recommends which model to use based on your state and house size.
- Installation Location: Another great thing about tankless water heaters is space-efficient. You can install them almost anywhere with a source of water and fuel and enough ventilation.
1. Rheem Performance Self-Modulating Tankless Electric Heater
BEST OVERALL
This Rheem electric tankless heater is our top choice for many reasons. It has a great price of just over 500 hundred bucks and can provide hot water for up to 8.8 GPM, enough for five showers and two faucets simultaneously. It is compact, electric, easy to install, and does not need venting. Keep in mind that it requires 150 amps and a 4 x 40 amp double-pole breaker.
2. EcoSmart ECO 27 Tankless Water Heater
RUNNER-UP
Energy-efficient, compact, and with electronic temperature control, you are sure to get endless hot water in your place. This tankless heater can produce between 2.7 and up to 6.6 GPM depending on its use. It is the right choice for an entire home in warm weather or small places like apartments or cottages in cold weather. It only needs 113 amps of power and a 3 x 40 amp double pole breaker to operate.
3. Rinnai 199,000 BTU Natural Gas Interior Tankless Water Heater
MOST EFFICIENT
This highly rated Rinnai water heater is not only energy efficient but powerful, compact, and sleek. It produces up to 9.4 GPM of hot water on demand and has a minimum temperature of 98 degrees and a max of 185 degrees Fahrenheit. Plus, it comes with a temperature lock feature to avoid accidents. It is fueled with natural gas and needs a concentric vent system.
4. Rheem Platinum Natural Gas Indoor Tankless Water Heater
BEST FOR NATURAL GAS
This Rheem Platinum water heater is fueled by gas and can get up to 9.5 GPM allowing you to use up to four different outlets of water simultaneously. Thanks to its PVC venting run system, this can be installed anywhere in the house, including the basement. This unit is ENERGY STAR certified and tech-friendly if that wasn’t enough. You can control the heating system from your phone when you buy the EcoNet WiFi kit.
5. Rinnai Value Series 120,000 BTU Tankless Water Heater
BEST FOR PROPANE
This is for you if you don’t have a natural gas line already in your house and prefer to have propane over an electric tankless water heater. This Rinnai water heater uses liquid propane, is highly efficient, produces 5.6 GPM, and can be installed in places such as crawl spaces. Plus, it comes with an electronic display and antifreeze features.
6. Ecotemp 37,500 BTU Liquid Propane Outdoor Tankless Water Heater
BEST PORTABLE
The Eccotemp portable tankless water heater is a must when you spend time outdoors and need a hot shower. It is easy to use, and all you need is a water source, of course, and a tank of propane gas. It is lightweight, compact, and easy to use and install. Best of all, it is affordable.
7. Rheem Performance Tankless Electric Water Heater
BEST FOR SMALL SPACES
This is the perfect size for an addition to your house or small cottage. This Rheem electric water heater can run up to 3.1 GPM, warm the water up to 140 degrees Fahrenheit, and it is compact and small that can fit inside a cabinet. Plus, venting is not needed and is compatible with ½ inch water connectors.
8. Stiebel Tempra 29 Plus Residential Electric Tankless Water Heater
MOST COMPACT
Stibel is a pioneer in tankless water heaters systems, and this Tempra 29 model is a reliable unit to have in your home. This model is super compact, energy-efficient, and delivers up to 6 GPM. Note that this small but powerful machine requires a minimum of 200 amps to operate and its own 3 x 40 breaker.