Top positive review
Inexpensive and lacks a thermostat but does the trick.
December 4, 2016
******As an update to review below: After a few months of troublefree operation, the unit has begun to randomly open the internal hi Temp switch. It works fine if I reset it. Happens maybe once a week or so. Contacted Bosch and everything checks out ok. But it still trips now and then. suspect the flow valve switch - a weak point on any of these type units. frustrating. *****
its small and neatly packaged to provide hot water for a remote sink. I installed it on line leading to my my kitchen sink/dishwasher.
All the plumbing lines were right there in utility room below my sink. As in any electric tankless, you need electrical power. I had an unused 240 circuit with 8 AWG wire from an unused electric range plug (we have gas range) and it was right by my install location - perfect - you need to consider your power line. This unit requires a cold supply line.
Pros: (1) At 1 gpm, I am getting up to a 60F rise, which is plenty. It is good looking and quiet. Install is pretty easy if you you are handy. I took the opportunity to replumb some 40 year copper lines and it went smooth but took several hours. DO NOT FORGET to place a water filter in the cold supply line to the unit (years experience with tankless). I made the final connect using stainless corrugated line made specifically for tankless heaters.
For those who do not know heat transfer, 9.5kW should be enough for one sink (60F rise at 1 gpm). Do not try using it for a shower - unless a 1 gpm shower is ok. At 1.5 gpm (if you can get it), the rise is only 45F. The tradeoff in tankless is temp rise versus flow rate.
Cons: (1) the US9 requires 0.75 gpm just to turn it on. Thats a good stream. For my kitchen sink, that's fine. But i would have an issue with this if it were in a bathroom where I sometimes want just a trickle. Others on market have a lower activation gpm. (2) it has a sizable pressure drop across it. I have 55 psi at the supply and can only grab 1.1 gpm max. I am sure my Kohler faucet is involved - preinstall, it had a flowrate of 1.5 gpm. (3) it uses 1/2 inch fittings. This could be a pro for many, but not for my install. (3) the unit is not thermostatic. You will always get the same temp rise, so you can get some pretty hot water! Careful of scalding! Better units have a temp limiter, such as 120F or 140F (ouch). For this reason, you should not attach to a hot water line as a booster.
None of the cons are disqualifying for me. Your application may vary. Now, how long will it last?