Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater, Twin Pipe

I installed this on my own with my Pops. Was quoted at $3K-4K to get it professionally installed. I specifically called Rinnai customer service about the warranty being void if it isn't professionally installed and they stated that this was not true. (although everywhere you look it says it should be installed by a professional) It is only void if it is found to be installed incorrectly. It was a ~$2K risk I was willing to take. The install was straight forward. Expect a couple trips to the local hardware store and some frustration but it truly isn't that complicated. Just read through the manual, it is pretty in depth and helpful. Fired the machine up for the first time and it ran like a champ. Shut the water off and turned it back on - it gave me error code 11 and wouldn't work again. Turns out my furnace (rated no more than .5 PSI) has been running on 2 PSI of natural gas for many years and the Rinnai was having none of it. It's rated for about .1ish to .4ish. Bottom line is it's worth a call to your local gas company to make sure you'll have the right pressure and supply. Once I had the pressure adjusted, it worked immediately. It has been running as expected the last couple days. There is a slightly longer delay to get the hot water (worst case, 2 stories up, morning, takes about 50 seconds to get hot at the faucet). But, this is something you'll want to come to terms with and for me, I'll take the savings over time. But 50 seconds is worst case, most of the time I don't even notice. I also did get the condensate neutralizer kit. Seems overpriced, but I didn't want to risk damage to any drainage pipe/septic tank. We have a well and sediment is what got our last tanked heater so I do plan on flushing this device at least twice per year. I think that is what gets a lot of people. Need to maintain your equipment so it can help maintain you!Pros: Efficient, small, accurate temp control, "endless" hot water, informative manual, good customer serviceCons: Small increase in time it takes to heat water, very slight dip in water pressure2 YEAR UPDATE:Overall, I've been extremely pleased. I have had zero issues with this water heater. Some notes:- This thing absolutely sips natural gas. To put it in perspective, only two devices use gas in our home - The water heater and a ~25 year old furnace (yeah, it's on its way out). During the winter our gas bill can be upwards of $90 for cold months. In the summer, when the only device using any gas is the heater, our bill is as low as $12 and that's with an $8 flat fee. Every home and family is different - we only have two adults and no dishwasher. But, I'm very satisfied and believe this thing will pay for itself.- I flush the water heater twice per year. This seems to work well. Personally, I wouldn't want to do it less frequently. We have well water and it's pretty hard. Once per year I will open it up and inspect the internals.- Speaking of a well... This is important information if you have one, too. If you're familiar with how a well works, the well pump kicks on when the pressure dips below a certain threshold and pumps water into the system until the pressure rises to another threshold, then stops. The heater must adjust the burners as the pressure increases to keep the outlet pressure at a steady temperature. The heater tries hard to do this, but isn't perfect. We have a shower probably 6 feet of pipe away from the outlet. In this shower, you can hear the well pump turn on and the pressure increases. The heater keeps up, but actually overshoots some. It's not scalding hot, but it's noticeable. So, it gets hotter for no apparent reason if you're not expecting it. This is ONLY true for appliances/sinks/showers RIGHT next to the heater. We have another shower directly above (10-14ft of pipe?) and the temp change is non-existent. The temperature dissipates by the time it gets there. I don't mind this, I actually kind of like it, but I completely understand if someone would be bothered by this.

I love this tankless heater!When I moved into my new home, I didn't realize how old it's water heater was. It was so old and filled with sediment I has maybe 15mins of hot water. So I decided to upgrade to something where I could use as much hot water as my wallet would allow! So I shopped around extensively. The local shops in my area had stupidly limited selections and high prices. So I took my search online. Amazon offers TON of tankless heaters at pretty good prices. After tons of review searching, making sure to filter out fake reviews, this unit really stood out as wildly successful for other. Plus it came in way under my 2k price limit. So I pulled the trigger and got it.Had it installed a couple weeks after I got it along with a water softener and I am so pleased.This unit is able to keep up with multiple appliances running at once. I did a load test with my washer, shower and dish washer running at the same time. All had decently hot water, but slightly diminished. I was getting maybe 110 degree water, which is reasonable. My house only has one bathroom so my load test was the worst case scenario. If you live in a house with multiple bathrooms tho, I don't think this is for you. You'd water something beefier. For me, this works greatMy only gripe with this is I wish the unit would allow for higher heat. It caps out at 120 degrees F. Which is decently hot but for cleaning it's often helpful to have 130-140. You can hack it to go that high and many people report it being just fine, but that does me no more warranty.I highly suggest using a water softener in conjunction with this unit if you live in a house with hard water. For me I live in Update NY and get treated lake water which is quite hard. Otherwise this unit will start to become less efficient after 3 years and will clog up with sediments after 7 years. Then you'll have to have it flushed with acid.Something else to be aware of:You may know this already if you are re-searching tankless heaters but it does take some time for it 'catchup' once you turned the hot water on. And how long it takes depends on the flow rate and distance from the heater. I had my heater located closest to my bathroom. My tub takes ~ 4 secs for hot water. My kitchen sink is the furthest from the heater and has a pretty slow flow rate. It takes ~ 32 secs to get hot water.I had this installed in March and haven't had a single issue with it. Running like clockwork.My energy bill dropped in half after installing this. Which makes sense. I live alone and work 10-11 hours every day and shower once a day. When I get home I use cold water to cook or wash my hands. So really on an avg day I am only using hot water in the morning for a shower. That's a whole lot of energy waste for a tank based water heater. Plus I get a $200 rebate which is nice.

Rinnai RUC98iN ULTRA is a perfect fit with vertical and horizontal vent pipes that are not supplied with the heater purchase.pipes are about $100 for the pair,but what's included is all the drains worth not less than $160,and are not offered by other manufacturers.Unit was installed by pros within 5 hrs.Total cost to me incl. install. and canadien tax[paid cash for install] was$2300 which i consider a bargain in comper to cumbersome traditional 60 gal .and it works very well.

Upgraded from hot water tank to on demand and really like it. I did my research and found Rinnai was one of the best in terms of reliability and performance. It's made in Japan which provides me some assurance of quality like purchasing a Honda or Toyota. Time will tell the whole picture but currently after a month, I am happy with my purchase and upgrade. Amazon is great to deal with.

Awesome savings on Hot Water Heating! Great quality too!

Simply installed it turned it on and it has worked perfectly ever since. Only thing is if you are having a shower and someone turns on and off another tap temp gets way hotter may have to install a separate temp regulator.

Placed order, only to be told the unit was not available. Price was too good to be true. Don't know the actual reason, just seems a bit shady.Exercise caution with these guys.