Rinnai 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!

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.

We have 6 kids and had my adult son and his wife living with us. So all In all we had 9 people 2 dogs and a lizard in this house.I Installed it myself converting from a 40 gallon tank heater. I would not say it was a breeze but it also wasn’t that bad. To be fair I am a mechanical engineer and am handy around the house. I would not recommend this as a DIY if you have problems with IKEA furniture. You will need to understand vent sizing calculations to determine if you need a 3” or 2” vent. Depending on where you put it you will need to be comfortable punching holes in the exterior of your house and installing the vent and intake in an appropriate manner to not cause a hazard. I had to run 3/4” gas lines as well because the old heater had 1/2” gas lines. (Don’t try and get by with a smaller line even if your neighbor said you can). Also as an FYI make sure you have a 3/4” full bore valve. Lots of gas line valves say 3/4” but only have a 1/2” bore on the ball valve. This will create a restriction in flow and cause you to throttle your gas flow unintentionally potentially causing issues in the combustion chamber during high gas demand times.All in all it was worth it. Before purchasing I would recommend having the system fully thought out.1. Gas flow - do you have 3/4” or larger gas lines you can tap into. What parts will you need to get the gas line to where you need it (valves, tees, reducers, flex line, fittings…)2. Venting and intake - where will you vent the PVC pipe out of the space. (Do not vent into galvanized pipe it will corrode out and damage your house) you will need to maintain drainage of the exhaust line condensed gasses. How many elbows and tees will you need, 3” or 2” pipe or are you using the 2 in one pipe.3. Venting and intake out of the house - there are safe configuration and unsafe configuration of how to exhaust the gasses out of your house. You also need to consider how to get clean intake air in. Don’t kill your family with CO because you were too cheap to design your system correctly.4. Drainage - this system will require a drainage system for the condensed gasses to drip down. During peak operation this can be a substantial amount of liquid.5. Power - you will need a GFI protected 110V outlet close to the mounting location.Do your homework and do it right and it will go smoothly. If you can’t do it right then hire someone to do it.