This 4 gallon mini-tank heater is perfect for my kitchen. The total cost for the tank and the installation was about $325.00—higher in my case because the tank did not quite fit under the sink and I had to move it to a cabinet 6 feet away, on the other side of the dishwasher. This added the cost of two 6 foot hoses, two brass connectors, and a 12 guage extension cord. The normal cost would be under $300. I opted to abandon the hot water at the sink and run only cold water into the mini-tank. This way, running hot water in the sink never impacts my gas water heater. The downside is that I can run out of hot water at the sink, if I use too much at once, but the upside is that it saves a lot more energy and water. By turning up the temperature on the Bosch to ¾, I have eliminated the chance of running out for my own needs. My sink is located about 30 feet from my water heater, which is actually more like 40’ of piping. It was taking a good 30 seconds to get hot water every time, and I started collecting the 2 gallons of wasted cold water for my outdoor garden. Now the hot is basically instant. Because of the unusual 6’ distance, it takes one second to get hot water. If it were under the sink it would be quicker. Installation was quite easy. Even with this less desirable location, the hoses and extension cord passed easily behind the dishwasher. I did it myself, no plumber or electrician required. Why not get a demand water heater for the kitchen sink? Money. Any demand water heater you buy will require a new, dedicated electrical line with a dedicated breaker. This will easily cost you $1500 or more for the electrician to install it. A demand water heater retrofit really only makes sense if you are replacing your main water heater, and in my case, I would STILL want my mini-tank, because the distance problem would not be solved. It would make some sense to have a demand water heater installed at the sink for NEW HOME construction, but the retrofit is far too expensive to justify. Now that I have converted my sink hot water usage from gas to electric, I can start working on converting to solar. Get this mini-tank. It will save you water and energy, even if you connect it to the hot water line. What you will need for a standard, under-the-sink installation: 2 ½”npt to 3/8” compression hoses, 2’ long 1 3/8” compression tee 1 3/8” female to female connector (male on both ends) Aluminum water heater pan You will use the connector to connect the 2’long 3/8” hose to the hot water hose for the sink tap. For my installation, I used the following: 2 ½” npt to 3/8” compression hoses, 1’ long 2 3/8” dishwasher supply hoses, 6’ long 3 3/8” female to female connectors, two to connect the 1’ hoses to the 6’ hoses, 1 3/8” compression tee 1 12 gauge extension cord, 8’ long Aluminum water heater pan Depending on your kitchen and location, you may want to plumb a PVC pipe into the over-pressure valve and either to a floor drain or to the outside. My kitchen has waterproof tile floors, so I can take a chance on an overflow filling the drain pan and spilling out onto the kitchen floor. I can just mop it up. I connected the 6’ DW supply hoses to the 1’ hoses. It was the easiest way to get the long 3/8” compression hoses to connect to the ½” npt connections at the water heater. Oh also, you need a good flashlight or headlamp, and a couple of pairs of adjustable spanners (small crescent wrenches). Note: Technically, you will need an electrician to install the 7 gallon version, but it does not require a new or dedicated circuit, as it still only pulls 12 amps. If you are comfortable connecting the electrical line into your existing box, you will be OK. Add a little cost for connectors or possibly a larger electrical box. In some municipalities, you may need a permit and inspection because this may qualify as adding an electrical circuit. The 7 gallon would be nice, but it also takes longer for the tank to heat and takes up more room. All good products though. I updated this on 3/19/2022 to correct some typos.
