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    Eccotemp FVI-12-NG Tankless Water Heater Review

    EccoTemp FVI-12-NG

    The Eccotemp FVI-12-NG tankless water heater is an indoor tankless water heater designed to service households with small-to-medium hot water needs. It uses natural gas as a fuel source and is capable of effectively delivering hot water to homes where more than 1 hot water application is used at the same time, such as a shower and a faucet.

    Eccotemp offers both a natural gas and liquid propane version of the FVI-12 model, this gives the homeowner the option to select the fuel source that best meets their individual needs.

    Eccotemp FVI-12-NG

    Our Rating           



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    Eccotemp FVI-12-NG Review

    At a Glance

    Fuel: Natural Gas

    ​Dimensions: 25"H x 15.5"W x 6"D

    ​Weight: 33 lbs

    ​Venting: Power / Non-Condensing

    ​Efficiency: 79%

    ​GPM: 4.0

    ​Made in China


    • Separate Controls - Both the gas pressure and water temperature can be regulated separately.
    • Precise Adjustments - Both the temperature and water flow can be adjusted to an exact setting.
    • Digital Display - Displays the temperature of outgoing water.
    • Vent Kit Included: A stainless steel horizontal vent kit is included. However, a vertical kit is available.
    • Ignition - Electronic ignition system ensures that the unit uses gas only when  heating water.
    • Power Ventilation - Improves safety and efficiency.
    • Water Fittings - True 1/2" NPT water fittings.

    Image Gallery

    Click image to enlarge images of the Eccotemp FVI-12-NG

    EccoTemp Control Panel
    EccoTemp Top
    EccoTemp Bottom
    EccoTemp Back
    EccoTemp Side
    EccoTemp Vent Kit

    Company Information

    ​Eccotemp Systems, LLC is an American company founded in 2004 by Mike Elrod, with the goal to deliver "a state of the art tankless unit at an affordable price point."

    The company's mission is to deliver a "whole house tankless water heater to the homeowner for the same price as a standard water heater." ​

    We have found Eccotemp to be very responsive to customer inquiries thru the chat option on their ​website, as well as by email. 


    ​A 2-year limited warranty covers the heat exchanger and other parts of the Eccotemp FVI-12, provided that the unit is installed and operated according to the company's guidelines. Click HERE to see the warranty.

    It should be noted that Eccotemp recommends flushing the unit every 3 months to prevent lime scale build-up.  Failure to do so may void the warranty.​


    4.0 GPM Gallons Per Minute
    79 % Efficiency
    74500 BTU British Thermal Units

    ​The FVI-12 can achieve it's maximum flow capacity of 4.0 GPM with a 45-degree Fahrenheit temperature rise.  If the unit needs to increase the incoming water by 77-degrees F., the flow rate drops to 2.3 GPM.

    A standard household 120-volt electric outlet is required. When the unit is operating it will pull 10 watts, and 2 watts when idle.

    We contacted Eccotemp directly to find the minimum activation necessary for the tankless to operate. They provided the following answer:

    The FVI-12-NG "is not a flow based unit, it is a pressure triggered unit. If you cannot achieve and maintain adequate water pressure, your water heater will not function properly or not at all. You need to have a minimum of 40 pounds per square inch (psi) of water pressure to activate and sustain operation of the unit."

    The tankless unit will need to be installed near a standard household 120 volt outlet as it will use electrical power to operate the internal exhaust fan and digital display. 

    This video from Eccotemp shows the internal parts of the FVI-12.


    This no frills tankless water heater has a sleek, modern design, and the low entry price  makes it affordable for nearly every budget.

    The Eccotemp FVI-12 comes with everything you need, including the horizontal stainless steel vent kit, and 110 volt UL listed power cord. 

    Eccotemp promotes this unit as being perfect for "vacation cabins, cottages, and smaller homes." We tend to agree. This unit isn't going to be able to deliver hot water to satisfy the majority of homes on a daily basis, but in situations where it won't be overly taxed, it's definitely worth a second look.​

    Eccotemp FVI-12-NG


    • Vent Kit included
    • Low price
    • Electronic Ignition 
    • Small, compact unit with a modern, sleek design


    • Recommended flushing every 3 months
    • Efficiency rating of 79% - low for gas tankless units
    • No internal freeze protection

    Final Thoughts

    ​With a maximum flow rate of 4.0 GPM and a maximum BTU rating of 74,500 the Eccotemp FVI-12 will definitely have difficulty keeping your household's hot water hot anytime it becomes taxed. 

    We are also concerned about the quarterly recommendation to flush the unit. In some areas this may be necessary, but the industry standard is to flush on an annual basis. 

    Still, we think the low price makes this a nice starter or low-usage tankless. It may not have all the bells and whistles, but in many situations they just aren't necessary!​

    How Does the Eccotemp FVI-12-NG Compare?

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    EZ Tankless

    EZ 202





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    2 years

    15 years

    5 years

           * Heat Exchanger Warranty 

    Other Resources

    Here are some other resources from our blog to help you make an informed buying decision.