Rinnai V53DeN Natural Gas Tankless Water Heater - 5.3 GPM, Outdoor Installation

Installed this in November 2018. Been hassle free, working perfectly since then. Love the endless hot water, and being able to refill the hot tub with hot water is great.We have extra hard water, so I flush it with 3 gallons of pure food grade vinegar every 6 months. This is critical, but also really easy, once you set up isolation valves and get a good little pump and a 5 gallon bucket. I flush with the heat on, set to lowest temp, only takes 20 min to run clear. New instructions say to run it cold with heat off, last unit we had in 2001 said to let it heat the vinegar for faster cleaning.Not an easy DIY install, especially the gas line upgrade. I had to run 60ft of 1 inch gas line at the last house, was a difficult job. Many cities don't allow homeowner gas line work, I got lucky and was able to get permits in 2 cities over the years.Vent kit install was fairly easy, out a side wall, cut a big hole in the wood rim joist. Needed to drill and saws all through 6 inches of wood, took a while, but pretty basic.You need to do a lot of planning and make sure your vent is not too close to a window. Check with your city first to learn their requirements, they can vary a bit.Lots of plumbing had to be moved/replaced, as we moved the location about 8 ft away from the old one.Even with all the work, the payoff is worth it. Endless hot water, lower gas bill, and about an extra closet of floor space gained. That was huge in a small living space.

We got a incredible deal. Bought a returned open box. It was brand new at half the price. Works great. Easy to install and quickly heats water.

Buy it. We have a much bigger rannai on primary residence and it is 12 years old and I've never serviced/flushed it as advised. We (2 teenagers me and wife) have had zero issues and the gals take lots of long showers, shave or whatever. Bought this one for a weekend tiny house/Park model RV/trailer. Much smaller capacity than my primary residence unit but happy to see it was the same quality, basic physical size and function . Just hook up 120v to unit for the ignighter, plumb in your gas and water lines and fire it up. Runs shower, kitchen faucet and bath faucet all on full hot with 115 deg water with no issue. Only have 3 fixtures so not sure how many more it could handle. Factory preset to 115 deg but changeable with dip switches to hotter or cooler. Came very securely packed. I installed service valves but will likely never service it. If I can get 12 plus years out of it without paying it any attention I'm happy. Doesn't come with a temperature controller but in 12 years we've only touched the one on my other unit when we moved it to paint the wall. We keep it set to 115 or maybe 120 default to be safe for any kids. That's too hot to hold your hand under anyway so never had a need to adjust. We have this unit plumbed to standard 20lb/30LB propane cylinders and it doesn't mind. Gained a free closet by replacing our tank unit with this one mounted on the outside wall instead of the inside wall.

install was fairly painless as far as the unit goes. I chose this as the time to learn to solder plumbing so that stretched things out. I move my water lines and got a bigger gas line to replace the one going to the old hot water heater.I ran it for 2 days with no vent on it. I just kept the back door open so no chance of carbon monoxide poison. I wouldn't recommend doing this but I'm OUTRAGEOUS!!Unit worked fine. washed a few loads of clothes. dishwasher and a couple showers. No problems. I wish it would get 10 degrees hotter. 120 is not quite good enough. I guess there's an Addon to make it go to 140 which would be nice. sucks you have to pay more for it.!!!!!!! IMPORTANT !!!!!!It doesn't come with a vent kit And the instructions all refer to their vent setup.Here's the important thing!! Its a direct vent unit. Not knowing what that meant I connected a 5" vent to the unit. It slides right in past the rubber gasket. Perfect fit I think.Turn on the hot water and 20 or 30 seconds later BOOOOM!!! it blows up. Well that was scarey. Panic and look for a fire. shut off the gas. nothing really looks wrong so I try it again. Booom. hmm.I called roto rooter on a sunday before memorial day and a guy comes out and tells me its back-drafting because my gas line is to small.I change to a bigger supply line.Boom.... Glad he didn't charge me for the service call...OK so now im going to call my hvac buddy to come out. But in the middle of the night I have an epiphany. The 5inch vent pipe coming out of the top of the unit has a smaller 3 inch pipe inside.Its the 3inch inside pipe that is a vent. The outside is actually the fresh air return.See new houses are well sealed and if the unit didn't have its own fresh air return it would create a vacuum in the house and not work.Sooo. I ran a 3" pie from just the exhaust of the tank and left the fresh air open to pull from inside the house. We are in an old condo that is far from sealed so no issues with a vacuum.muahhahaha,. working like a champ now.So what was happening was with a 5" pipe around the whole thing it was trying to intake and exhaust through the same pipe. It would blow out the flame because there's not enough oxygen in the exhaust gas. Then the gas would build up and the ignitor would kick in and blow it all up.