RU160iN Condensing Tankless Hot Water Heater, 9 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!

This unit outperformed my expectations in a big way. I live in the mountains at 8,000 feet and my cold water comes from a well. In the wintertime, the water is MAYBE 40 degrees when it comes out of the tap. I figured with a 7 gallon/min rating and the incredibly cold ground water, I would be lucky to get 3 or so gallons/min, which would be enough for a single hot shower. Nope! I've had no problem running two simultaneous showers along with the dishwasher in the wintertime. How this thing manages to heat the water by 70 degrees instantly is beyond me but it sure does!I had very minimal plumbing experience but I had no problem installing the unit after doing 10 minutes of YouTube research. I love the fact that the exhaust vent just uses standard Schedule 40 PVC, which is super cheap and easy to work with.As you can see in the pictures, I added a pre-filter to reduce mineral scale buildup as my ground water is very hard. I just swap out the cartridge every 6 months, just like the cartridge in the fridge. After 9 months of use, the unit hasn't yet told me it needs any descaling, but I expect that will come up by the end of the year. The procedure there is very simple.Otherwise, this is a very compact, very attractive unit. Zero issues after 9 months of continuous use.

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.

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.