Rinnai RU199iN Condensing Tankless Hot Water Heater, 11 GPM, Natural Gas, Indoor Installation

October 2023 - The takeaway is that anyone who complains about these not working well did not install it correctly (and won't admit it). I am shocked at how well this thing works. I am still amazed how quiet it is. No further occurrences of errors. Works fine with furnace running even supplied through a 1/2in tee from a 1 in main supply to the basement. Sep 2023 Brief update: I had one occurrence of error 12 - flame out. But it hasn't happened again. I hope it was a fluke caused by our gas supply and nothing else. If not, I'll investigate and update my review afterward. Original review Aug 2023: My recent experience with the Rinnai RU199iN tankless hot water heater has, in a single word, been excellent! It's like the ninja of water heaters - quiet and incredibly efficient in performance. Getting it up and running was straightforward, similar to the typical expectations of setting up the necessary plumbing, gas, venting, and electrical work. However, it's important to note that this isn't like replacing a conventional tank where everything falls into place easily. Rather, it is like a fitting jigsaw puzzle into place, not easy per se, but not too daunting either. The most fun was renting a rotary hammer from Home Depot to bore the vent holes though brick. For anyone worried about gas lines like me, you may appreciate this little surprise. The unit appears to have an internal gas booster pump. Ingenious, right? I chose to run it off of an existing gas line which was originally fed from a 1-inch line from the meter, with a brief downgrade to a 1/2 inch, before returning to a 3/4 inch. Despite my initial concern, it seems to function flawlessly under these conditions. But I am not complacent, and plan to eventually test all my gas appliances together in full throttle, just to be certain that the supply line capacity holds up. One of the most commendable features of the Rinnai RU199iN? Stable hot water output. Not once did I experience any hot water fluctuations during use. An absolute win! However, I did notice a slightly longer delay to get hot water on a cold startup, taking approximately 10 to 15 seconds longer compared to traditional heaters. But once it gets going, it provides steady, continuous hot water supply. Oh, and I must add - I did the installation myself. So, for all the DIY enthusiasts out there, this little project is quite manageable and rewarding. In conclusion, the Rinnai RU199iN tankless hot water heater has proven to be a stellar addition to my home. It delivers consistent performance, minimal noise, and solid dependability. If what you're after is a top-notch appliance that couples functionality with ease of use, then the Rinnai RU199iN certainly fits the bill. Five stars for this one, without a second thought!

First tankless with new build. Very happy after six months. Tankless is definitely the way to go. Plenty of continuous hot water and lower natural gas bill. Takes up less space in garage. Rinnai appears to be high quality. Friends recommended and say the same, trouble free. Highly recommend.

Seems like a good product. Was disappointed to find I was missing the union fitting for BOTH isolation valve upon arrival, as if it hadn't been packaged. Consequently had to reschedule all work for switch over to be done until after I get a hold of manufacturer. Looking forward to getting this running and will update my review at such time. Edit: After contacting rinnai, they sent me out the missing valves, albeit begrudgingly. The unit fired right up and I noticed no difference in time to receive hot water at fixtures. VERY quiet. The most inaudible gas appliance I have ever owned. Instructions were clear and very descriptive.

2yr ownership update: Aside from one breakdown due to a faulty part (which was immediately shipped by the manufacturer under warranty) this heater is amazing. Perfectly maintained hot water temperature for as long as you need it. Can run a bath, shower and dishwasher etc and not a slightest drop in hot water pressure. Awesome! I completely recommend this heater without any hesitantion. Our home is 4 bedroom single family home with 2 main bathrooms and 2 smaller washrooms. Firstly, the positives; Fast to heat up (within 1 minutes 2 floors above) Endless flow of hot water Can have 2 showers working and haven't really tested how many faucets we can run at the same time It is quiet and does exactly what we bought it for The only negative was the ordering process. I chose a water heater from Amazon that had a connected Amazon Installation Service option which I chose. The heater arrived quickly and in good condition. I called the Amazon approved contractor to confirm its arrival and they sent someone to come and install it. When the person came, they stated that they did not realize that it was a tankless heater and refused to install it unless they supplied it themselves. All down to Warranty issues apparently. Seeing as our existing electric tank heater had broken down2 days prior, we were left with an issue - no hot water and 3 young kids to keep bathed. I asked them to take a look at the electric heater to see if there was a fuse or something that may have gone wrong. They said that they could book the job for $150 and take a look at it but that it would most likely be the internals. (as it was, when we eventually managed to get a local installer for the new heater, he made the effort to come down and take a look at the existing heater. It was a case of taking off a small panel (4 small screws) and pressing a reset button. Sure enough, it sprang to life again) We then called Amazon to ask them to recommend another installers. The chap who dealt with us at Amazon installation services called around all the local plumbers and none of them would install a tankless heater that they had not sold. Amazon said that they would refund the installation fee and give us a $30 credit for the hassle. After a bit of phoning around we found a local plumber to do the work. I called the actual water heater manufacturer to check that the warranty would still apply and they confirmed that so long as he was a registered professional plumber then he could sign off on the warranty sheet. So the 5 stars is for the heater and only 1 star for the Amazon Installation Service

I got a quote from a local plumber to remove a tank and install a tankless water heater but it was more cost effective to purchase this unit and have it installed. The same company agreed to charge labor only and installed this unit. Buying this unit and paying for installation only saved me a least $1,500 off their initial quote. It took them the better part of a day but it works great and I am happy with my switch to a tankless unit. And further saving on costs, my gas company gave me a nice rebate, I got a tax credit when I filed my taxes, and I'm supposed to also get a rebate from Rinnai (they are stalling and definitely take quite a long time with lots of follow-up.) The only downside of this tankless heater is that in the winter, it takes about 15-30 seconds longer for hot water to get to two floors above the unit (it is in the basement.) Sometimes the temperature slightly fluctuates a bit but it's not a big deal to me. Overall happy with my purchase and hopefull it will last a long time - just have to flush it at least once a year (soft water in my region.)

Easy to install if you already have the proper size gas line to it. It does what it says it does and gives plenty of hot water for as long as you need it. Depending on the GPM of the unit, it will do multiple fixtures. No complaints there. For mine, after a month to a month and a half, the unit stopped working. There was power to the unit, water went through it, but no longer any hot water. Apparently, there is a spinner just past the cold inlet and filter that "twirls" when water goes through it and that is what signals the heater to ignite and light the burners. If any debris or whatever clogs the "twirly" thing, water will still flow but it won't "twirl" enough to light the pilot and make hot water. This is a horrible design flaw because it is so common from what I can tell on fix-it boards. I have City water, with a water softener, and never had any trouble with my tank water heater. There are videos on how to take the valve apart and clean the debris out, but this shouldn't be happening so many times on a brand-new water heater. Utterly ridiculous. Service appointments cost money and take time for a silly design flaw.

We purchased this tankless water heater in 2020 after going through 3 traditional water heaters in 9 years. This tankless water heater has been amazing for our family of 8. 4 years in it is still going strong. We no longer run out of hot water while trying to get the whole family through showers and baths. The output is plenty for almost everything with a few caveats. The first is we can run two showers simultaneously without any noticeable decrease in water pressure but when running all three there is a significant drop in water pressure but additional units can be chained together to solve that problem. The second issue we've had is with our front-load washing machine. I'm not sure if it's just our model but for whatever reason if we run two showers with the washing machine you can tell every time the washing machine starts pulling water. The dishwasher and sinks don't have any noticeable impact to water flow. So if you want to run more than two showers at a time you may want a second water heater but for our family of 8 this product has been amazing!

We bought and installed a Rinnai RU199iN in 2019 and as of today we could not be happier with it. In my initial review I mentioned that the water pump is audible, but this turned out to be negligible, and in our case, mostly due to the installation location of the unit. We really have no complaints after six years of use. Below are a couple of reasons why we love the water heater: - The water gets hot very quicky, the unit turns on the moment water flow is detected - Two people can shower with ease there is enough hot water (and this is in an old house with partially some 70-year-old galvanized plumbing - Endless stream of warm water (well that is the point of a tankless water heater I guess) - Very low maintenance: We live in SoCal and have the unit in a closed and unheated cabinet outside. I installed a warming lamp that kicks in when the temperature is below 40°F. The only maintenance is to change the in-line water filter once every year. The recommendation is for 6 months, but since we only are the two of us, replacing the filter annually seems enough.

Easy to install, works well. We have replace our Bosch with this machine. Very please with it. Be careful with the condensing water, there is a lot. We had to 3D print part to collect the water. But nothing you cannot buy. The most difficult part was to find the System 636 gas pipes (or other certified gas pipe). 2" pipes are best and very easy to use with this unit. After that ready to roll and WIFE happy.

Installed for almost a year no issues. Love it

Easy to install by a plumber/gas fitter, takes very little space, easy to operate.

Installed this myself. It was pretty straight forward, with a bit of plumbing knowledge. Instructions were very clear and easy to understand. The only thing that wasn't mentioned was the fact that you need to neutralize the condensate (very corrosive to plumbing). I used the Axiom NC-1W and would recommend this to anyone.

The product was delivered on time and was in good shape. The only problem I had was that the distributor had included an old manual with the heater. The installer had to spend two days trying to figure out that some of the parts shown in the installation diagram were not required (they were not easily available either). My installation was delayed by 2 days. Finally, we called the Rinnai call center and they sent us the correct manual.