Rinnai RUCS65IN Tankless Hot Water Heater, 6.5 GPM, Natural Gas, Indoor Installation

This is a contractor grade unit, no frills or options. I replaced a tank style unit with this model and I can't tell the difference. It provides hot water when I need it. You must purchase a valve kit to install this unit. It must be back flushed just like a coffee maker. It is very quiet. This unit is a condensing type unit so it collects moisture that must be drained. The base unit does not have a control panel. The temperature is set by dip switches. A control panel add on is available. No wifi function on this model. I would purchase this again.

The pros:-Fairly easy install but requires a number of fittings.- once installed- works great.- able to use a portable propane tank to run for long periods of time. Mine 100lb tank.- excellent on demand hit water.- low temp exhaust- just use a pvc pipe with thermal tape.- intake- pvc with a screen to prevent debris- very simple and cheap.- no need for special exhaust and intake plumbing fixtures.Cons-- must be installed properly- do highly recommend a professional.- buy a water pressure regulator- water pressure impacts the way the unit works.- ensure the proper gas pressure- also key to make the unit work.- make sure the settings on the unit are properly set to your condition- dip switches.- power- use a properly grounded power source- very important as well.

Technology in these tankless units is so advanced from what was available 20 years ago. Impressive.I am a DIY home owner. Was faced with a leaking tank style water heater and found that power-vent style tank heaters were becoming difficult and expensive to buy. Seems like the on-demand heaters was the way to go. This Rinnai unit is a very good value in my opinion. Priced at the lower end, while having impressive features when compared with other manufacturers.My caution to others is to be prepared for expensive installation costs. Plumbing and exhaust changes in my home added up to over $200 in parts plus significant labor to do things right. This is not a fault of this particular unit. It is simply a general reality when converting from a tank style heater to one of these tankless units.I highly recommend buying the recommended valve kit for about $50. I did not buy the kit and was out over $100 with brass hardware to perform the same level of isolation and service connections.Review of the RUCS65iN model: Very pleased with its performance so far. (First week of operation) The Installation manual is organized well and has the info needed to guide a proper installation. It took me a bit to understand rules and restrictions for the exhaust / combustion piping, but the manual did help me get there. Make sure you have sufficient flow at your faucet to get past the minimum flow required before heat kicks in. Once heat is being applied, the unit will automatically adjust the heat input to match the water flow rate such that output temperature is precisely 120 degress F. (Can select higher temps with dip switches.) I was impressed with the amount of condensation that drained out during operation. This unit is so efficient with its heat transfer. PVC pipe works great for exhaust and barely warms up during long operation.

I bought this to replace a smaller Rheem. It worked well for approximately 18 months, with a few minor annoyances. First one was in order to get hot water in the kitchen, we had to turn on a bathroom faucet, so Rinnai's claim of working well with lower water pressure aren't accurate. Irritating, but not necessarily a deal breaker. Another annoyance was the fact that you can't adjust the temperature lower than 120 F. I called customer service and was told to install a mixer faucet. I was hoping to use the line I had installed for the previous Rheem to use outside for washing pets. I had to replace that due to the water being too hot for that purpose. Annoying, but not that big of a deal. Well, last month the unit had a small explosion inside that burned up all its wiring and likely ruined the control board. The explosion was significant enough that it shook the house, knocking things off of the shelves. I called the propane company out and they pressure tested the line up to the unit and found no leaks. That means of course that a leak developed inside the unit. At the direction of Rinnai I had their technician come out to look at the unit. He had no way of testing it, just eyeballed it and stated that he didn't think Rinnai would back their warranty on it because the units are tested at the factory. He stated that he would contact them and find out. Three weeks have gone by with no word or contact from either Rinnai or their technician, so we have to assume that they have no intension of backing their own warranty or of dealing with the situation in any way. Now keep in mind that this was an explosion in their unit. A situation that could have burned down the house causing injury or death, but this company wasn't even interested in taking the unit in to inspect it. I would be satisfied if the company had just gone this far. If at this point they stated that the unit didn't have a leak, I would accept that there must have been a leak below the unit that caused the buildup of gas in the bottom of its cabinet. Keep in mind however that the unit was perfectly installed and maintained, and still had rubber gaskets in place in the bottom where the wires exit, so the likelihood of propane, heavier than air, somehow wafting upward into the unit is extremely low.This water heater was over $1,000. at the time. It was installed with all proper clearances. It actually exploded under strange circumstances. While it worked adequately for 18 months, not as well as the lower priced Rheem, but acceptable, the fact that I am still paying for it on my Amazon account and it is a pile of junk that could have burned our house down, and that Rinnai couldn't care less about the situation, makes it a scary choice for anyone.

The tank was easily installed but took about $800 in parts to convert my plumbing from a tank heater to this tankless. The one issue I have is on occasion I'll turn the faucet on at hot and I'll not get hot water unless I turn off the water faucet and then turn it back on to max hot. Also, more often than not, it I switch the faucet from running cold and slide it over to hot, I get no hot water until I turn off the flow and restart on hot. There is no tepid water temperature ( you know, in the summer when you want the water cool but not cold. Not happening. You get hot medium hot or cold. If you want tepid, turn on the bathroom sink to run hot so the heater stays on and you can get a cool shower.