Bosch Thermotechnology 7736505868, 4.5kW, Bosch US4-2R Tronic 3000 Electric Tankless Water Heater, 4.5 kW, 6.6" x 12.8" x 2.9", White

I was looking for days for a device that had the following characteristics: No water storage tank, small size, instant hot water, easy installation, to use in a sink. And this team was the best I found. Additionally, the brand gave me security. It has worked flawlessly since installation over a year ago, which is why I bought one more.

EDIT: The unit is dead. The plunger that mechanically turns heaters on and off based on water flow has slowly stopped retreating after water shut-off which triggers thermal cutoff.Tronic 3000 models without thermostat will only work well only in specific, narrow, circumstances:constant water flowhigh water flow to reliably turn on the elementsconstant inlet water temperatureDeviation from above will cause temperature to fluctuate to uncomfortable levels.The unit itself is very simple in design: flow switch that engages, mechanically, via plunger, one or two switches that turn on the heating elements. This design suffers from turning off the heat too late which results in hot wave when turned on soon after, before elements/water inside of the unit cools off. On the positive side, I think the flow switch is well made, and of different design than other heaters I've seen and hopefully it'll last longer.Due to temperature fluctuations and no thermostat I would definitively not recommend it for shower installations. Otherwise, if you can maintain the flow and don't mind the 'heat wave' this unit will work with a sink, however, in my opinion it's overpriced for what you get (at this price other brands offer electronically controlled temperature).

I put this on the sink in my shop. First off, it did not work at all. I then found that the factory side of the wiring that goes into the junction block was never connected in the block. I fixed that, then... With the high/low switch on high, if I run the water as slow as I can, so the valve in this heater opens to turn on the heater, it will WARM up the water. It does not make any HOT water. I wasn't expecting this to heat the water to hot, but it barley warms it. Maybe only one leg of the 240v system is working. I have about 16 days left in my 30 return window to decide what to do with this not very impressive unit.Here is an update.I contacted Bosch, and talked to Matt (multiple times) in the tech dept, who was very helpful. After some testing on the unit, it was determined that the wire that should be connected to the heating coil, was not. It looked like it was, but was hidden under the wire cover. He wanted me to ship this back to Bosch. I noticed that the box it came in had an X drawn in pen on the front, and what appeared to be a defective merchandise label on it. I think someone else bought this unit, it didn't work, and returned it to Amazon, who then resold it to me. Bosch sent me a new one, and this one came with the factory wires in the junction block not connected, and a screw holding the heating unit to the backing plate was stripped out and floating around the unit. They sent me another one, and this one seems to be working much better. You can't run the water wide open, but slow it down a little and it warms the water good enough for hand washing. Matt said there have been a lot of assembly problems, that they are trying to fix. Maybe some of the other bad reviews here had this same problem. Call Bosch and they will work with you to get it fixed.

You do have to be able to wire the 240V service or you will need an electrician. This is not plug and go. It will work great for one sink or one shower, it will not heat more than that. We installed it on the dog wash station in or kennels. Works great, puppies have warm baths.

I am normally against electric tankless frankly they don’t get hot enough, don’t last long enough and do not provide enough gpm. This one totally outperformed the eemax installed originally, upon inspection of components during install this is a rather simple functional tankless and really should work for a long time to come!

I purchased this unit in Feb. 2022. It worked great for the first couple dozen times I used it. I had it installed in my heated shop and used it a time or two every week basically for hand washing and then it stopped heating. Today I finally had time to call about the two year warranty dept. and was told that I will need to hire a certified technician to come to the shop and and call their technician to trouble shoot with them and get this…. There is no reimbursement from Bosch for me hiring the technician. I mean it did work for approx. 6 months so the installment had to be correct from the get go. This is a $185 unit so I would of thought they would have replaced the unit. I’m undecided on what to do now but leaning towards just buying a different brand. Any suggestions? Bosch I would of thought you would be better than this!!

It will cost you almost as much for everything to install it (to code) as it costs. By the time you buy the GFI 30 amp circuit breaker and the hoses and the installation it gets up there. After running all to code it gives you hot water at a very slow rate, luke warm at a hand washing rate, and just takes the chill off at wide open. Don't expect too much, it's ok for a shop but I wouldn't want one in my bathroom and no way could it fill a tub. Probably won't use them again.

I loved the size and ease of installation and operation perfect for my needs.Fast service and good price!!!