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Availability:
In Stock.
Arrives
Thursday, Oct 29
Set name: 3.6GPM NG NEW
Features
- Endless Hot Water for Home Multi-Scenes: Boasts a max 3.6 GPM and 80,000 BTU for 23 taps (shower + kitchen sink + bar)no more hot water shortages for daily household use.
- No Sudden Temp Changes, Stable Experience: Advanced tech maintains steady water temperature; no sudden spikes or dropsideal for showering or bathing infants comfortably.
- Cut Down Monthly Utility Bills: Heats water on-demand, cutting standby energy waste versus traditional tank heaterslowers monthly gas/electric bills and supports eco-living.
- Space-Saving for Small Spaces: Compact wall-mounted model fits apartments, small homes, or renovationsfrees up floor space while providing reliable on-demand hot water.
- One-Click Specialized Modes: 4 preset modes (Dish 100F / Fruit 95F / Infant 104F / Elderly 107F)no manual adjustments needed for different daily needs.
- Save Money on Extra Costs & Energy: Kit includes exhaust pipe (no extra purchase needed); its oxygen-free copper tank cuts heat loss to lower energy use, fitting standard 1/2" NPT water and gas ports.
- Professional Installation Advice: Must be installed by licensed professionals per local building and plumbing codesnot recommended for areas above 2,000 feet elevation.
Description
80,000 BTU Water Heater 100,000 BTU Water Heater 130,000 BTU Water Heater 190,000 BTU Water Heater 130,000 BTU Water Heater 190,000 BTU Water Heater
Brand: Ranein
Power Source: Natural Gas
Product Dimensions: 13.8"W x 21.7"H
Special Feature: LED Display
Color: Gray-NG
Power Source: Natural Gas
Special Features: LED Display
Voltage: 120 volts_of_alternating_current
Flow Rate: 3.6 gpm
Maximum Temperature: 149 °F
Heat Output: 80000 british thermal units
Maximum Pressure: 150 psi
Mount Type: Wall
Item Dimensions W x H: 13.8"W x 21.7"H
Material Type: 3.6GPM 80,000 BTU (Indoor)
Brand Name: Ranein
Model Number: RH8K-NG
Number of Items: 1
Unit Count: 1 Count
Manufacturer: Ranein
Manufacturer Warranty Description: 2 Year Manufacturer
Included Components: Assembly Kit x1, Manual x1, Tankless Water Heater x1, Vent Pipe x1
Color: Gray-NG
Style Name: Natural Gas
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Thursday, Oct 29
This item is non-returnable:
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
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
Set name: 4.3GPM LPG
So far it works well and the exhaust installation was simple. Extensions are available. The heater is responsive to even small flows. It responds to increases in flow by increasing the heat so the temperatures do not fluctuate. The connections are 1/2”, requiring finding 3/4 adapters if going with the usual flushable install kit. The threading is not NPT tapered so the adapter should have a stop with washer, but many layers of tape or the horse hair method works with a standard reducer. There is no remote available, after every power down it defaults to 129°f, so it needs a convenient location to put it back to the temperature you want if it is higher. 149 is max which is what works for us. Make certain you pick the right gas, they are not changeable and not returnable. Amazon refunded me and I got two for the price of one. I found someone to donate the LP version to. We used the 4.2 gpm version for a single bathroom apartment. More than enough for multiple water draws simultaneously.
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Reviewed in the United States on July 1, 2026 by Daniel Huntsinger
Set name: 4.3GPM LPG
2nd edit!—— it’s been almost a year and want to say through the winter I was almost certain it was going to be broken with the water frozen even inside the house, we had issues with the gas company (propane) blot being able to come fill so we went without heat off and on all winter, we ended up just filling a 100lb cylinder every 2 days 😳 it was expensive. But during the times we didn’t have heat and inside froze my fridge broke, (water and ice don’t work) all shut offs busted when we got heat and water thawed. But the shut offs to this didn’t! And it didn’t break! We’re still going strong and still working properly 🙌🏻 Editing to update, it’s now been about 3 months and I love this so much! Bills went down about 100$ and it’s just perfect! I got this about 3/4 weeks ago it’s been installed 3 weeks or so. My dad installed and I was helping. It was easy to install and hook up. The packaging comes with everything basically, you need to hook up. I’m pretty sure we had to buy the shut offs. But either way it’s cheap and works great. I have 5 kids almost 6-11 years old plus 3 adults. So far no problems with it heating and keeping temperatures. It’s quiet and definitely space saving!!! So now I can use the bathroom closet instead of having a big tank taking up all the space. This is the propane not natural gas. Sorry for the long video review but wanted to let people to know some details cause I was hesitant my own self after reading some of the reviews. Questions for will it work or not work cause I was told by Lowe’s a few years ago I need a 9-11gpm for the people I have in household. It’s actually by faucets and the rating they have and how many you have and want running at the same time. So I bought all my fancy faucets (waterfall, rain shower head) etc from Amazon as well and they do take a good bit of water output so I just checked the output and f it, let’s give this a try. My main concerns was the reviews like “I got propane but it won’t work it’s only for natural gas” or “it leaks upon installation or after a few days” I’ve had it for almost 3 weeks and it’s been good to us no leaks nothing. I’d definitely recommend this tankless heater
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Reviewed in the United States on August 23, 2024 by Jessica williams
Set name: 4.3GPM LPG
The heater worked great till it broke, absolutely no customer service to buy a replacement part. A phone number that worked yesterday would not work today, tried for 3 days with no call getting thru to talk to an agent. Terrible customer service
Reviewed in the United States on August 18, 2026 by james tiglas
Set name: 3.6GPM LPG
I purchased this a year ago and got around to installing it in late August. Living in south Alabama, I figured this would work well for our home. For what it does, and the price of the heater, I’m very pleased. Tonight is the coldest that the water heater has seen. The water coming in was 62 degrees. The output was 127 with the thermostat set at 149. Two important things to note: 1) I have a ball valve in-line at the outlet and it is throttled back a little over half way. 2) I have a well so I don’t take showers because of the inconsistent water pressure (cut-in set at 40 psi, cut-out at 60 psi). Once I install a pressure regulator, showers will be okay. I’m giving it 5 stars because it does work, it has been cheaper to operate than the electric tank water heater that I’ve had, and it is very affordable. From September 1 through today, we’ve not used but about 8 gallons of LPG to heat water for my wife, myself, and grandkids. If you’re considering this, do be aware that 3.8GPM isn’t much water. I miscalculated the volume of water from this old well pump. In my own experience in process control, it was easy enough to regulate the temperature by throttling the output of the heater to get the desired water temp/flow rate through. So, be forewarned, if you don’t have low volume water, you may need additional throttling to slow the water down through the heat exchanger. I installed it myself within about 40 minutes. Very easy to install, however, at one point we did have LPG tank heater installed so the existing exhaust vent was used. This heater mated up perfectly with the existing exhaust stack so that was extremely beneficial.
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Reviewed in the United States on November 11, 2025 by X3n0N907
Set name: 3.6GPM NG
This water heater was easy to install. I used the template that came with the unit, worked well. It takes about 40 seconds to get hot water other than that it works well.
Reviewed in the United States on September 4, 2026 by Jerry L. Althiser
Set name: 5.3GPM LPG Outdoor
The Ranein water heater is working great, I have had it for about a month and a half what a change the old electric water heater if you took a shower you had better be done in 10 minutes or it turned cold, with the Ranein you can stay in shower as long as you want too, wife was running hot water in the kitchen, washer doing a load of laundry and me in the shower I felt no difference in water temperature, so happy with this heater, well worth the process of changing from electric to propane, installed be myself other than the propane hooked up by the propane company!
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Reviewed in the United States on July 29, 2026 by Amazon Customer
Set name: 3.6GPM LPG
My twenty year old 40 gallon (traditional) hot water heater finally sprung a massive leak, leading me to research LPG heaters that were available. My recollection is that the heater cost around $300 in 2005. The local big box hardware chains had heaters that began around 800 and seemed to accelerate from there. Since I live by myself, this seemed to be overkill, when I had the bright idea to look at tankless heaters. The chains had some that were even more expensive. Then, I checked Amazon. I found this 3.8 gpm / 80000 BTU heater on a black Friday price of $239, with a minor delay in delivery. For the price difference, I thought I would give it a try. I also ordered a HYDRO MASTER Tankless Water Heater Service Valve Kit (62.46) to provide fittings for the water connections. I waited a couple more days for my friend (Thank you, Andrew) to assist me in mounting and plumbing the unit in. His expertise, while not absolutely necessary, allowed me a two hour installation, with no leaks. He helped me determine additional parts necessary (PEX fittings, PEX hose, exhaust pipe and couplings available locally (around $120). (One caveat: when attaching the water valves to the unit, use teflon tape and teflon paste to seal. Do not apply too much torque when installing, it can be difficult to counter hold the connection.) All plumbed up, turned on the cold and hot water valves, plugged in the electric, turned on the LPG, no leaks. turned on the hot water spigot and the unit fired right up, I could not have asked for a better outcome. I noted on the outside of the cover, the date of purchase and the 1 year warranty. We'll see how long it lasts. Update: after 3 months of use, I have seen my propane usage drop precipitously. This unit is perfect for me and has already saved me the cost of the unit. Will keep you posted.
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Reviewed in the United States on December 9, 2025 by The Guy Who Owns Fast Cars
Set name: 4.3GPM LPG
Works well for shirt term hot water.
Reviewed in the United States on September 5, 2026 by digger