Ranein Natural Gas Tankless Water Heater, Indoor Max 4.3 GPM, 100,000 BTU Instant Hot Water Heater
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Availability:
In Stock.
Arrives
Wednesday, Jul 22
Recently Viewed
Color: Gray
Set name: 4.3GPM NG Indoor
Features
- Powerful On-Demand Heating: 100,000 BTU & 4.3 GPM for this tankless water heater gas, supports 3-4 water points simultaneously, delivers endless hot water on demand with no waiting.
- 4 Intelligent Preset Modes: One-click switch for 4-season/Kitchen/Bathtub/Shower modes; 4-season auto-matches temp, kitchen defaults to 100F, bathtub supports 50-800L volume adjustment.
- Precision Temp Control: Gas-water-temperature intelligent linkage, 95F-155F adjustable range, high-temp lock prevents scalding, safe for kids and elders.
- Oxygen-Free Copper Heat Exchanger: Enhances heat transfer efficiency, corrosion-resistant and durable; paired with enhanced combustion tech for energy saving.
- All-Round Safety & Anti-Freeze Protection: Equipped with dedicated anti-freeze device, resists 14F/-10C low temperature to effectively prevent pipe freezing and cracking; plus overheat, dry burn, exhaust blockage and low water pressure startup protection; powerful fan exhaust prevents CO leakage.
- Clear LED Display & Temp Memory: LED screen shows real-time water temp, operating status and fault codes; temp memory retains preferred settings, no repeated adjustment needed.
- Included Vent Pipe & Installation Note: Comes with original vent pipe (no extra purchase) for the indoor propane tankless water heater. Install by licensed professionals, not for >2,000ft elevation. Recommend draining water completely if temp drops below 14F/-10C or unused for long to prevent pipe cracking.
Brand: Ranein
Capacity: 4.3 Gallons
Power Source: Natural Gas
Product Dimensions: 14.17"W x 22.05"H
Special Feature: LED Display
Power Source: Natural Gas
Special Features: LED Display
Wattage: 7.8 watts
Voltage: 120 Volts (AC)
Flow Rate: 4.3 Gallons Per Minute
Maximum Temperature: 155 Degrees Fahrenheit
Heat Output: 100000 British Thermal Units
Maximum Pressure: 116 Pound per Square Inch
Mount Type: Wall
Is Electric: No
Smart Home Compatibility: Not Smart Home Compatible
Color: Gray
Style Name: Natural Gas
Brand Name: Ranein
Model Number: RH10K
Manufacturer: Ranein
Manufacturer Warranty Description: 2 Year Manufacturer
Included Components: Assembly Kit x1, Tankless Water Heater x1, Use’s Manual x1, Vent Pipe x1
Item Type Name: tankless water heater NG
Capacity: 4.3 Gallons
Item Dimensions W x H: 14.17"W x 22.05"H
Material Type: Natural Gas
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Wednesday, Jul 22
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
Color: Gray
Set name: 4.3GPM LP Indoor
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
Color: Gray
Set name: 3.6GPM LP Indoor
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
Color: Gray
Set name: 3.6GPM LP Indoor
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 Reviewed in the United States on November 11, 2025 by X3n0N907
Color: Gray
Set name: 3.6GPM LP Indoor
I’ve been using this Ranein propane gas tankless water heater for about 9 months now and I’m happy with this purchase. 6 months after purchase I did need to have a part replaced. The part could not be purchased at a regular plumbing supply store. I called customer service & they answered promptly and actually replaced the entire unit. It works well. Water pressure and temperature is great and consistent. You must plug it in to ignite the heater so you have to use electricity however, I don’t see much of an increase in my electric bill. I’ve used it with 30lb propane tanks and the propane lasted for 3 months with multiple individuals taking daily showers/ washing dishes. The 100lb tank lasted even longer. Overall I’m very pleased and highly recommend it. Took off 1 star because of having to replace the broken part after only 6 months.
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Reviewed in the United States on May 6, 2026 by Simone
Color: Gray
Set name: 3.6GPM NG Indoor
This product is what it says it is natural gas hook up 80,000 BTUs this unit is good enough to run laundry machine. I full bath in a few minutes. Endless shower approximately 123° perfect. The unit is very self-sufficient and remember to buy the connections they provide. Other than hooking it up to your waterlines in lit outlet very easy to follow instructions. FYI DIY compatible and do follow airflow instructions and don't forget about the bladder tank if you don't have one you'll definitely need if you have bladder water bad water pressure. Then after hooking up the natural gas line 2 unit double check for leaks you spray bottle with a little bit of dawn dish soap or dish liquid spray and watch for bubbles if no bubbles you are OK. Plug-in unit 120 outlet close by with a GFI do note that GFI should be on one breaker instead of existing plug. no need for wiring since it has a plug itself built in. Fits any exterior wall double chuck waterlines turn unit on by faucet automatically starts warming water. I hope this little review helped you out enjoy your blessed day , future pictures coming soon
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Reviewed in the United States on May 24, 2026 by Jay
Color: Gray
Set name: 4.3GPM NG Indoor
I replaced my 14 year old, 40 gallon water heater with this tankless water heater. Installed it my self using the 42 page installation instructions available on line from the seller. Venting requires category 3 stainless steel 3 inch hardware which is readily available on line but rather expensive. However any tankless water heater would have the same requirement because of the high BTU requirement. The vent pipe which comes with the unit has very limited application. The mounting hardware which comes with the unit is not practical unless you are mounting to a tile or masonry wall. I used a couple of 1x 4 boards that I ran horizontally and attached to the wall studs with lag bolts and then used short lag bolts to mount the unit to the boards. Installation was relatively easy; connected gas using a flexible gas line ( make sure it is rated for 100,000 BTUs). I recommend you use a polyphosphate water filter ( available from Amazon for $80) in line with the input water line to reduce scale problems that can occur with hard water. I really like the display feature of the unit. It shows actual water temperature as well as set temperature, water flow rate, and gas consumption rate. It is a great feature. I am using the unit in a house with 3 full baths and 3 adults. 2 people can shower at the same time and there is still adequate water for the kitchen. The 4.2 gpm flow rate is adequate for us. The unit does a good job of maintaining a constant temperature. I have the unit installed in the garage. It is relatively quiet and I don’t hear it running in the house. The exhaust fan is very quiet; the loudest sound is just the water running thru the unit. I highly recommend this tankless water heater.
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Reviewed in the United States on February 27, 2024 by MCS
Color: Gray
Set name: 3.6GPM LP Indoor
We have a really nice bathroom for a hipcamp operation but there was no practical way to get hot water to it. I was amazed at how many people took cold showers, so I set to solve that. This water heater is awesome it works very well, the showers are plenty hot, and we have a lot of happy campers. We raised the overnight stay rate from $28 to $34 / night and peopel are happy to pay a bit extra for a shower, and they stay longer. The small investment in the heater will pay off in the end. We had a leaky pressure relief valve. I tried all the customary fixes to stop the steady small drip, but sent a note to the compay. In the interim, I went to Home Depot, grabbed a new relief valve and installed it. I sent a copy of the invoice to the seller and they refunded the cost to our account. It's hard to beat that. All in all a good product for a fair price. We're very happy.
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Reviewed in the United States on July 25, 2025 by Thud
Color: Gray
Set name: 4.3GPM NG Indoor
It's working well, it just beeps at me and stops heating when I've washed my hair for too long. I turn the water off for a minute, turn it back on and it's back. Update. I won't change my original rating because the performance is fine, and I'm not sure how long it would last if I had a water softener. Indianapolis has very hard water, and now, 14 months later, after the 12 month warranty is up, the tank is leaking. Do not recommend a budget water heater, tankless or otherwise unless you have a water softener or live somewhere with softer water.
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Reviewed in the United States on February 22, 2026 by jd