Adding another mini-tank water heater

Over the last two years, we have progressively developed one of the most complicated water heating systems in the world. At least it feels that way. I have written previously about our problems with our defective tankless water heater and its recent resolution. As much as we love our tankless heater, there is no avoiding the fact that they pretty much suck when it comes to the little stuff (i.e. handwashing and dishwashing). They require a minimum flow rate to kick on and a sustained flow to stay on. If you aren’t using a constant stream, as with a shower or filling a washing machine, you will end up with a pattern of hot/cold/hot/cold/hot water in your pipe. While this is tolerable for washing your hands, it can be a real shock when you’re trying to shave.

Because we don’t like the idea of wasting a ton of water just to keep a steady stream running through the heater, we put a mini-tank (Ariston GL-4) under our sink about a year ago. It is fantastic! It provides a nice buffer for the tankless, and is seriously “instant” (hot water in a couple of seconds). Although it introduced a tank to our tankless system, these heaters are very well insulated and we noticed no change in our electricity usage.

So, after a year of getting used to the luxurious hot water at the kitchen sink, we began to wonder what it’d be like to have instant, buffered hot water in the bathroom. Although I had conditioned myself to a routine of shaving only after a shower and carefully using the residual hot water in the pipe to fill the sink and rinse my face, I thought it might be nice to be able to shave any time without wasting a lot of water waiting for the hot water to get all the way across the house or to wash our hands in actual warm water. The distance problem, of course, plagues any variety of water heater, not just a tankless. Anyway, since we are also in the process of adding a half bath on the 2nd floor, we decided to add a 6 gallon Ariston (GL-6) in the basement to feed the basement bath, the main bath, the new half bath and a potential future laundry room and wet bar (once we get the rest of the house done). I started the install last weekend…

The hardest part (emotionally) was tearing out all the plumbing I had worked so hard on in the past. Since I had not foreseen the additional bathroom when I laid it all out and had since changed some ideas about the basement bathroom (future remodel), I decided to start over. This always sounds like a good idea and feels like a bad one 9 hours into the replumbing when you still can’t flush a toilet! Copper takes such a long time that I am really warming up to the idea of PEX, which I’m going to try for the first time for upstairs. Getting rid of most of the connections sounds great! Here is the first stage of the carnage…



Here’s the cleared out ceiling. You can see the before picture here.



Heater and some of the plumbing installed:



Most of the pipes redone:



6 thoughts on “Adding another mini-tank water heater

  1. Je ne parle pas Francais (eh… seulement en peu) mais, merci beaucoup pour visitez-nous a “” 🙂

    Did I just butcher the French language? If so, I apologize. It’s been a long time since I’ve had to conjugate French verbs!


  2. I have to laugh! We moved into a new home, replaced old furnaces with high efficiency ones, tore out three big old water heaters and installed a Takagi tankless (all ourselves). Since we do dishes by hand, and turn off the shower while soaping up, it became clear (and cold) very quickly that this would not work for our lifestyle. The Takagi does not keep heating water unless you have a .6 gallon or higher GPM, which I never have while rinsing dishes. So we ended up buying a 6 gallon electric water heater, which we use only as a holding tank. It is plumbed so that when the thermostat in the neutered electric holding tank goes below a certain point, a pump turns on that runs the water in the holding tank back through the tankless at a high enough flow to cause the tankless to turn on. This heats up the holding tank high enough to keep a steady flow of hot water when it is run through a mixing valve. The entire system is then further complicated by having a segment that goes off to heat one room of the house that they installed radiators in, and which was heated by the third hot water heater. The copper pipe, valves and gauges in the furnace room would make NASA jealous!


  3. Hello! I’ve been following your website for a while now and finally got the bravery to go ahead and give you a shout out from Humble Texas! Just wanted to mention keep up the great work!


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