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Natural Gas Tankless Water Heater - ORBEK 100,000 BTU Up to 4.3 GPM Indoor Installation - CSA Certified On-Demand Instant Hot Water Heater 3/4" NPT Connector Size

  • Based on 237 reviews
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Style: Natural gas


Material Type: 100,000BTU, 4.3GPM, Indoor


Features

  • Endless On-Demand Hot Water: The Orbek tankless water heater gas provides up to 4.3 GPM and 100,000 BTU, serving 2-3 fixtures simultaneously for comfortable use throughout your home
  • Safety & Reliable: The Orbek tankless gas water heater is CSA certified and packed with advanced safety features, including dry combustion protection, overheat protection, water leakage protection, flame failure protection, and high water pressure protection etc
  • Energy Efficient: Crafted from high-quality oxygen-free copper, the Orbek heat exchanger delivers superior heat transfer and corrosion resistance. It can adjust between three heating modes to meet seasonal hot water needs, saving energy costs for you
  • Compact Design: With a compact size of 20.5"H x 13.0"L x 7.0"W, gas tankless water heater indoor saves over 50% of space compared to traditional tank water heaters, fitting easily into most corners of your home
  • Stable Temperature Control: The built-in chip adjusts heating power 20,000 times per second, keeping water temperature stable within 1F for a comfortable shower experience
  • LED Digital Display: The Orbek natural gas tankless water heater indoor features a clear screen for sensitive temperature adjustments between 95F and 149F. The power outage memory function ensures you won't have to reset the temperature repeatedly
  • Water Pressure Range: The Orbek tankless water heater natural gas indoor is equipped with low water pressure start technology, allowing it to operate at water pressures ranging from 15 to 150 PSI, even in remote homes far from city centers. Additionally, the operational noise is very low, ensuring it will not disturb your family
  • Easy to Install: Fits standard 3" OD vents, 3/4" NPT fitting size, and 120V AC. Suitable for most homes. Vents and water valve kit not included but we are also selling this. Recommended to be installed by a professional for better performance and safety
  • After-Sale Service: We offer 2 years coverage for the whole machine, 5 years coverage for the heat exchanger, and long-term Professional technical consulting services.

Brand: Orbek


Product Dimensions: 13"W x 20.5"H


Special Feature: 2 & 5 Years Warranty, 24/7 Customer Service, CSA Certified with Many Protections, Compact Design & Easy Installation, Four Seasons Function See more


Color: White


Wattage: 17 Watt-hours


Brand: ‎Orbek


Product Dimensions: ‎13"W x 20.5"H


Special Feature: ‎2 & 5 Years Warranty, 24/7 Customer Service, CSA Certified with Many Protections, Compact Design & Easy Installation, Four Seasons Function


Color: ‎White


Wattage: ‎17 Watt-hours


Voltage: ‎120 Volts (AC)


Maximum Flow Rate: ‎4.3 Gallons Per Minute


Maximum Temperature: ‎149 Degrees Fahrenheit


Heat Output: ‎100000 BTU per Hour per Foot per Degree Fahrenheit


Efficiency: ‎[High]


Maximum Operating Pressure: ‎150 Pound per Square Inch


Mounting Type: ‎Wall


Is Electric: ‎No


Manufacturer: ‎Orbek


Item Depth: ‎7 inches


Item Weight: ‎25.9 pounds


Item model number: ‎HW100


Special Features: ‎2 & 5 Years Warranty, 24/7 Customer Service, CSA Certified with Many Protections, Compact Design & Easy Installation, Four Seasons Function


Included Components: ‎Tankless Water Heater x 1 User's Manual x 2 (English and French Version) Quick Installation Poster x 1 Assembly Kit x 1


Batteries Included?: ‎No


Batteries Required?: ‎No


Date First Available: December 22, 2023


Frequently asked questions

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This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Top Amazon Reviews


  • Works at or above spec given my setup
Style: Natural gas Material Type: 80,000BTU, 3.6GPM, Indoor
I bought this awhile ago but just installed it. I’ve only got a 1/2” gas line running about 90 feet from the meter @ just under .26 psi and the 80K BTU unit can handle 2 fixtures continuously which is 3.5 gpm. I’m in the yellow zone so it’s working at or slightly above the stated spec which is great. I’ve also got it set to 118 degrees which is above the factory setting of 107. If I try a 3rd fixture it still works but it drops the water temp to accommodate —it doesn’t shut down which is nice. It was easy to install as I had all the connections there and the integrated cord meant I didn’t have to wire a cord to it. Gas is tricky so unless you’ve got all your numbers and calcs done, it’s easy to be disappointed with the performance. All the numbers I quoted above are very important before trying a tankless and the reason I didn’t go with a lager unit. Be aware. So far so good now let’s see if it lasts. ... show more
Reviewed in the United States on September 10, 2025 by Krame

  • Excellent customer service!
Style: Propane Material Type: 120,000BTU, 5.1GPM, Outdoor
I own two of their water heaters, one with electric heat and this one using propane. They were well supplied with parts and any owner supplied parts are easily obtained from Amazon or Lowes/HomeDepot. The propane unit sort of worked but was having issues and soon stopped to ignite at all. I contacted customer service and received a prompt reply. It was quickly determined by them to replace the unit and they sent a shipping label for the return paid by them. They were aware as soon as it was in the UPS system and shipped the new one. Regardless there was an issue, it can happen, it's the best customer service experience. The replacement unit was easily installed in 15-min and for several weeks now its working without issue. The electric unit has had no issues. I'm quite happy with the units and the company. I will note that the names Fogatti and Westinghouse appeared in service communications or on return label. ... show more
Reviewed in the United States on June 27, 2025 by Gary W Gary W

  • Great heater at a great price!
Style: Natural gas Material Type: 100,000BTU, 4.3GPM, Indoor
We've had an on demand water heater installed for years now. This one replaces the last one after it failed during a flood occasion. The new heater is even better than the last at a really good price. Reinstall was simple and the controls are easy to use. If you have a tank hot water heater, try this one! It will save you money on gas and take up much less space. Recommended! ... show more
Reviewed in the United States on August 29, 2025 by Richard Sutton

  • Zero Stars If I Could – Worst Purchase Ever
Style: Natural gas Material Type: 100,000BTU, 4.3GPM, Indoor
This water heater has been a disaster since the day I bought it. It runs for two minutes, then errors out. Every time I need hot water, it’s a fight. Customer service promised, “Don’t worry, we’ll take care of you!” but their “solution” was a video for a different model showing settings that don’t even exist on this unit. When I told them it didn’t apply, their response was to ask me for a video—like the problem is me, not their defective product. Insulting and useless. This heater is garbage, and the support is worse. It’s getting worse by the day, and I’m done wasting time and patience. Save yourself the nightmare—don’t buy this product. ... show more
Reviewed in the United States on September 20, 2025 by Sara

  • On demand water heater
Style: Propane Material Type: 120,000BTU, 5.1GPM, Outdoor
Good heater, need to tape and putty joints to prevent leaking. Otherwise works good for small mobile homes.
Reviewed in the United States on September 27, 2025 by George Mattos Jr

  • Works good
Style: Natural gas Material Type: 100,000BTU, 4.3GPM, Indoor
So far so good , until works well and I get plenty of hot water .
Reviewed in the United States on October 13, 2025 by John Lesmeister

  • good little unit
Needed to replace a 13KW heater that quit after some years of service. Liked this one since it was 14KW and had a 3.6 GPM flow rate. I'm limited to a 60 AMP breaker and this seemed to be the best alternative. Installation was quick and easy. Long hot showers aren't a problem. I had needed a flow restrictor on my tub with the old unit and it took forever to fill. I found that the next larger restrictor works with this unit and tub fills more quickly but a restrictor is still necessary as I would expect it to be with any smaller water heater. Can't speak to longevity yet but so far really like this little heater. My old one only showed the desired water temp. This one shows actual temp which is kind of cool. ... show more
Reviewed in the United States on March 7, 2025 by rich odonnell

  • Orbek on-demand
Style: Natural gas Material Type: 100,000BTU, 4.3GPM, Indoor
Installation was simple. At this early stage, performance is as expected.
Reviewed in the United States on October 4, 2025 by Eric

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