Rheem 18kW 240V Tankless Electric Water Heater, Gray

This unit works very well for my 3 bed/2 bath 1400 sq-ft home. I’ve been running it for a couple of months now to see how well it was going to handle the whole home. Set at 140° it handles two showers at the same time with some hot water to spare for say the bathroom sink if needed. Rarely do we need any extra than the two showers. You do have to be careful when running a tub of water as some faucets can outflow this unit. I have to run our garden tub about 3/4 from wide open so the water stays hot. If your using this for a whole home unit I recommend setting at 140° or 135° but nothing lower. I tried 130° and the two showers were hard to make warm with straight hot going in both. At 140° you can split hot/cold so both get fair amounts of hot water. My only complaint is as other mentioned LED lights will flicker when it kicks on as it takes 75 amps of power to run. I installed this myself with a friend to help run wire, and as long as you know what your doing it’s very easy to wire up. DO NOT ATTEMPT IF YOU HAVE NO ELECTRICAL KNOWLEDGE. Please have it professionally installed if you have any doubts. If you do install yourself make sure and read what size wire it takes as it needs bigger wire than your traditional tank water heaters.Overall I’m very pleased with this unit as we have 5 kids so running the dishwasher, doing laundry, and bathing can use A LOT of water for us and the 50 gal water heater we had just couldn’t keep up. This one is doing great and haven’t noticed any significant water temperature fluctuations other than maybe for the first week which I call a break in period. One shower could get hot then cold several times before getting out. But after the first 4-7 days of usage it leveled out and a hot shower stays hot no matter how long or short it is. Hope this helps anyone looking into these water heaters!

I changed my old tank water heater for this wonderful tankless. I have earned a lot of extra space in my laundry. Energy consumption decreased because it works only when you use some hot water. For me and my wife we use around 20 minutes shower hours per day,for both. So,the water heater stay on very few hours unless when faucets are in use due to cold weather. In principle,I have found great advantage changing water heater system. Very easy to install,following electrical instructions is essential,use new 40A (2x) breakers and correct number 8 wire (4x) to connecting the electrical switchboard and the tankless water heater. No noise is perceived during operation. Easy temperature adjustment. Here,in Florida I established 102/105F, during winter time. For summer time I will reduce to a lower temperature. It consumes 18KW and 75A (very high) but for too short period of time x all day lower KW and A for tank system. I fully recommend if in your location is allowed due to the cold weather (please consult the tankless chart provided by Reheem).

Update: Ended up being a blown fuse. Replaced and working well now.Bought two of these for our cabins and has been working fine til a storm and now they both will not work. Displays will not come on at all. Lights only flickered once and all other appliances are fine. Can't find a reset button and power cycling is doing nothing. $800 bucks down the drain and no hot water now.

New Review:Ok, this lasted 26 months before I finally ripped it off the wall and replaced it. It had failed three times in that 26 months, and this was the last straw for me.After almost exactly one year, one of the heating elements fell apart. It was literally in pieces. I replaced the bad element with a third-party element, and almost exactly one year later, the second factory heating element fell apart, too. My water has very low mineral content, but after the first one failed, I cleaned the elements every six months along with flushing the whole system. That still didn’t keep the factory elements from failing. The third-party elements looked fine. I bought some spares just in case.Finally, last weekend I started noticing that the water coming out of the tap was CRAZY hot. When I started looking for the problem, I found that one of the heating elements was stuck on all of the time. The water would just keep heating up inside until the thermal protection circuit turned it off. Something in the electronics had failed.There was another issue with the water heater unrelated to these failures, too. I have solar panels on my roof, and I found that whenever someone would turn on the hot water, the solar inverter would turn off. The water heater was injecting too much electrical noise onto my power lines, which the inverter didn’t like. There is absolutely zero electrical noise filtering on the water heater, so I added my own. This fixed the solar problem, but the filter that I added consumed some power all of the time, so it wasn’t saving me energy like I’d wanted.I replaced it earlier this week with a 24kW model from a different manufacturer thar I found locally. The new one, even though it has a higher power rating, uses nearly half of the energy required by the Rheem to take a shower, 7kW vs 12kW. Since it has a higher power rating, it’s easier to use hot water at multiple points simultaneously. It also has a dynamically adjusting flow meter, compared to the Rheem where I needed to add an external flow restrictor.Don’t buy this heater. Spend a few dollars more and get something that is built better, doesn’t constantly break down, and doesn’t cost as much to operate. Get a Stiebel Eltron Tempra 24 Plus, which costs a bit more up front, but works much, much better.Original Review:A week shy of one year ago, I purchased this to replace the old water heater in my home that had quit working. The installation was easy, it only took me an hour or so to swap out, and it worked great. For a year.My warranty will expire in three days, and the water heater stopped working a few days ago. It wasn’t completely dead, and it would heat the water to around 85 degrees, but that still makes a miserable shower.I called the warranty department, and they sent me a troubleshooting guide. Using this guide, I determined that one of the heating elements was open. Honestly, I didn’t feel like it was worth the effort of trying to get this fixed under warranty, so I ordered a replacement (two, so I could replace them both) 9kW heating element here on Amazon and they were delivered the next day.The maintenance instructions say that you should pull the elements out every 6-12 months and soak them in vinegar to remove any scale, but admittedly, I hadn’t done that. My water is very soft with a low mineral count, so I tend to neglect things like this.When I removed the bad element, there were no mineral or calcium deposits on it, but the element was in horrible shape. It was all burned up, with gaping holes, twisted metal, and exposed, broken metal coils. The other element looked perfect. The bad one looked like it had been in a furnace.I replaced the elements with new ones, and it’s operational again.I’m happy with this heater while it is working, but I don’t know if I’m crazy about possibly needing to replace the elements once a year. Hopefully, I just had bad luck with the one element.