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45H-NG 6.8 GPM WholeHome/Residential 150,000 BTU CSA Approved Natural Gas Outdoor Tankless Water Heater

  • Automatic temperature controls enable safe and convenient use
  • Can be used for 3-4 applications simultaneously
  • Anti-freeze function prevents unit failure during cold weather
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Product Details

About This Product

The Eccotemp 45H Outdoor Natural Gas Tankless Water Heater is one of the most advanced CSA approved outdoor models of the Eccotemp tankless line. Rated at an impressive 6.8 GPM with a temperature rise of 38 degrees and 140,000 BTU per hour, the Eccotemp 45H-NG can meet all your hot-water needs! Eccotemp's advanced 0.7 GPM low flow ignition technology allows users to enjoy endless hot water without experiencing cold spots.We recommend the Eccotemp 45H-NG for standard size single family homes, apartments, condos, cabins, as well as smaller commercial applications. Using 2-3 hot water applications simultaneously is a breeze with the Eccotemp 45H-NG. With our upgraded PCB (Product Control Board) performance and an all-new gas modulating valve, consumers can experience best in class temperature performance with a price anyone can afford.The compact, wall mounted Eccotemp 45H-NG has a 110/120-volt UL listed power cord that powers the internal Exhaust Fan, Anti-Freeze Protection, Digital Display and PCB. With its fully automated control system, the Eccotemp 45H-NG only pulls about .67 amps during operation, making it an ideal for low energy consumption and efficiency.


  • Rated for 2-3 applications used simultaneously means that taking a shower and running two sinks at the same time is effortless. The Eccotemp 45H is ideal for normal hot water heating applications in ANY size residential single-family home, condo, cabin, apartment, or Light commercial use
  • Rated at 6.8 GPM at 140,000 BTUs with a temperature rise of 38 degrees, this ultra-efficient tankless water heater is ideal for just about every single-family home in the US and Canada
  • CSA certified for installation in the US and Canada. This tankless water heater meets and exceeds all safety and efficiency requirements according to the DOE with an Energy Factor Rating of .83.
  • Advanced Generation 3 Computer board with high performance processing and smart adjust technology built in. Our proprietary developed programming meets and exceeds today's consumer demands
  • With advanced incoming and outgoing water temperature sensor technology, you always have total confidence when it comes to safety
  • Limited Manufacturer Warranty (Heat Exchanger: 10 Years, Parts: 5 Years), live chat, appointments for product support, self-help guides will give you peace of mind that the Eccotemp 45H will keep you in hot water for years
  • What's Included: 45H-NG tankless water heater, mounting hardware, gas appliance shut off valve and installation manual
  • The Eccotemp 45H can be complemented with our patented one of a kind EZ-Flush descaling kit to ensure your tankless water heater is running at maximum efficiency all year long
  • The Eccotemp 45H has been CSA tested and approved for US & Canadian use at elevations up to 2000 feet. Installation and use of the Eccotemp 45H above 2000 feet may affect overall product efficiency and performance. Installation and use of the Eccotemp 45H above 5000 feet is not recommended.
  • Click here to check out our buying guide on water heaters
  • Click here for more information on Electronic Recycling Programs
  • Return Policy

Product Information

Internet # 206028769

Model # 45H-NG


Dimensions: H 25.5 in, W 14.5 in, D 6 in


Product Depth (in.)

6 in

Product Height (in.)

25.5 in

Product Width (in.)

14.5 in

Vent diameter (in.)

0 in

Water Connection Size (in.)

3/4 in


Application Type


BTU Rating

140, 000

Efficiency Level


Finish Family


First Hour of Delivery (gallons/hr)


Flow Rate @ 35°F Rise (gallons/min)

6.8 gal (US)/min

Flow Rate @ 45° Rise (gallons/min)

5.8 gal (US)/min

Flow Rate @ 55° Rise (gallons/min)

4.5 gal (US)/min

Flow Rate @ 65° Rise (gallons/min)

3.2 gal (US)/min

Fuel Type


Gas Connection Size

3/4" NPT

Gas Type

Natural Gas

Heat Exchanger Warranty

10 Year



Maximum Temperature (F)

120 F

Minimum Activation Rate (gpm)


Minimum Temperature (F)

90 F

Number of Showers


Pack Size


Product Weight (lb.)

36.4 lb

Required Volt Connection

120 volt



Total BTU (Btu)

140000 Btu

Uniform Energy Factor


Vent Type


Water Connection Location


Water Heater Features

Freeze Protection, Wall Mounted

Warranty / Certifications

Certifications and Listings

CSA Certified

Labor Warranty

No Warranty

Part Warranty

5 Year

Questions & Answers

Q:What is the lifespan of this Water heater? Better than the traditonal tanked water heater?
by|Aug 3, 2021
1 Answer
Answer This Question

A:  We appreciate your question! Our water heater's lifespan expectancy is 12 years and up with proper yearly maintenance, descaling, and filter cleaning. The heater should also be installed in a non-corrosive and destructive environment to maintain its top-notch operation. Tankless water heaters are better than the traditional tank heater because these are now on-demand. Will only produce hot water when needed. It also saves space and is stylish. If you need anything else, please do not hesitate reaching ou ~ Team Eccotemp

by|Aug 3, 2021
    Q:The waterheater will not hold temperature.I called and made an appointment for the tech to call me back and never received a call .His name is John and he was supposed to call today between 10 and 10:30. Very poor customer support.
    by|Nov 5, 2020
    2 Answers
    Answer This Question

    A:  The very worst customer service ever. Had an appointment for a call back, hour and a half later she calls and lies about calling before. Ignightor died and the closest replacement is in China. If you don't want hot water stay with them. We bought a real water heater to install. Very costly $200.00 service call mistake to but this unit. Home Depot should be ashamed to carry such an inferior product.

    by|Nov 15, 2022
      1 found this answer helpful

      A:  Hello there! We do apologize for the inconvenience. Upon checking with our technician John, he has tried to contact you several times but no one is answering the phone. We can set another call appointment for you and have our technical support help you out. We are here to help! If you have any questions or concerns, please reach out to our technical support team via live chat, setting up a call, or creating a support ticket at support.eccotemp.com. We will be waiting and are always happy to help!

      by|Nov 6, 2020
        Q:I purchase this unit some time ago for a renovation project I am doing and I have reached the time to install. When I opened the box I noticed that there is no pipe housing cover, is there one available
        by|Jun 1, 2017
        1 Answer
        Answer This Question

        A:  Good Day, housedoctor! We apologize for the inconvenience however, what do you mean by pipe housing cover? For further assistance, please contact us at 1-866-356-1992 (Mon-Fri 9am-8pm PM EST) to speak to a representative or you can email us directly at support@eccotemp.com. Thank you! Eccotemp Systems LLC

        by|May 4, 2023
          Q:Can this be installed in my crawlspace ?
          by|Mar 27, 2017
          2 Answers
          Answer This Question

          A:  No, you cannot install in a crawl space. The exterior model needs exterior ventilation. You would need to buy the interior model and ventilate properly. To be honest, I bought this model, then returned it and spent a little more money on an alternate model, a Rinnai. This one you're looking at is terrible. The customer service from the company is terrible and they don't know what they're talking about. Take note at the amount of water needed to activate the heating device.

          by|Apr 23, 2019
          3 found this answer helpful

          A:  Good Day, Mike! For as long as you have enough space for combustion(oxygen intake) and has proper space to vent out the hot air. If hot air is not properly getting out of the crawlspace, it may suffocate the heater and may shut down. It needs more oxygen intake since it has dual burner. If you are able to meet these requirements, then you should be fine. Thank you! Eccotemp Systems LLC

          by|Apr 23, 2019
            1 found this answer helpful
            Showing 1-4 of 16

            Customer Reviews

            3.1 out of 5

            • 3.1 out of 38 reviews
            • 53% recommend this product
            Filter by:
            Showing 1-10 of 38 reviews
            Worst buy yet. Water heater won’t turn on unless 2 points are on. It won’t balance between cold ...
            Worst buy yet. Water heater won’t turn on unless 2 points are on. It won’t balance between cold and hot. I set temperature in but will normally give me way hotter water. I have to set it to a lower temperature so nobody gets burn when it does turn on. To get it to turn on I have to have shower and bathroom sink on at same time. Or bathroom sink and kitchen sink on at same time. It turns off on me all the time.
              DO NOT PURCHASE!!! heat exchanger totally rusted out only after 2 years, I called eccotemp the ...
              DO NOT PURCHASE!!! heat exchanger totally rusted out only after 2 years, I called eccotemp the very day I installed it and asked them about the water and cloud of vaper that came out of it everytime it came on and they said it was normal condisation, DO NOT believe them!! They will not replace or warrant it but did say they would sent me another one for the low low price of 499.99. oh and I had to spend another 98 dollars on sending it to them.
                8 found this review helpful
                The tankless water heater is exactly what we needed. Installation took several hours, by a profe...
                The tankless water heater is exactly what we needed. Installation took several hours, by a professional. It works great!!
                • Verified Purchase
                • Recommended
                3 found this review helpful
                Eccotemp products are junk
                If you’re thinking of purchasing an Eccotemp product, don’t do it. They’re all junk products. And the customer service that they provide is simply non existent. Buy a different brand. Eccotemp products are all junk.
                  Something wrong with the electric right from the start. Returned at the store with no problem. Can't get hold of manufacturer very easy to get help. Have to schedule a time for tech support
                  • Verified Purchase
                  Not the product I wanted to order. I was expecting to order the propane version. Which I thought I had ordered...
                  • Verified Purchase
                  The unit didn’t work right out of the box. I...
                  The unit didn’t work right out of the box. I tried calling tech support only to find out they only work thru email and take several days to reply to you. After several emails I finally got a tech on the phone who barely spoke English and had no idea how to fix the unit. He suggested I needed a part which would be under warranty because the unit was brand new but I had to pay for the part and then pay to mail the old part back to them to get a refund. Month later and still no refund. The part didn’t fix the problem so they told me to mail the whole unit to them. This interaction took weeks. We’re showering at friends houses the whole time. I finally said no more and went and bought a different brand. It worked great the first time. I’ll never buy Eccotemp again and would tell everyone I meet not to either.
                  Response from Eccotemp Product ExpertFeb 16, 2023
                  We do apologize for the inconvenience. If you are having problems with the water heater, please contact our Eccotemp HelpDesk from our official website. You can schedule a call or do a live chat with one of our technical support team or create a ticket by sending us an email. We are here to help!
                  ~Team Eccotemp. Eccotemp
                  • Verified Purchase
                  Rating provided by a verified purchaser...
                  Rating provided by a verified purchaser
                  • Verified Purchase
                  • Verified Purchase
                  So far it working great!...
                  So far it working great!
                  • Verified Purchase
                  Showing 1-10 of 38 reviews