Hot water heater automation

[sash]

true there added heating costs in the wintertime, but the same can be said about switching from incadesent to CFL or leds....or swapping out your old energy ineffecient fridge..  all equalls added heating costs in the winter time
 
but really are you heating 6 months out of the year ??  unless you live where I do then yes ( as i have snow on the ground for +6 months out of the year then yes maybe  but otherwise most people only heat 4 months out of the year..)
 
if you are looking at saving  cost on heating and hot water heating then install a simple air to air  heatpump that does  hotwater and  household heating as they give you COP of 4  as mentioned above  if you live in a climate zone of 5 or higher ( otherwise ground loop is better)  and that will be cheaper then natural gas at  .10kwh  or a couple of evacuated solar panels  they do 80% of your hotwater needs
 
for the last few years that is how I have done my house and water heating..  with an average winter temp of -17c  my house heating ( water and building) requirements is only 150$ per year  which is down from  1500$ i was paying  previously - for a house that is 1300sqf  I currently use  a 7kw heatpump  and 7kw of evacuated solar water heating panels to heat my house and my hotwater basically my heat pump only comes on from dec - feb the rest is heated by the sun

 

[LarrylLix]

If your water is that hard that you burn out elements in your water heater then a tankless water heater is not for you.
 
You didn't mention how you had to pump vinegar through the tankless elements every 3-4 months or it clogs up with lime and scale like a bad kettle with water that hard,
 
I have gone through two Rinnai units in the last 5 years here and I have soft water. I really doubt they save any money when the venting alone, cost me about $500 and the unit itself about 4 times the cost of a power vented unit. Too many moving parts switching a binary based bunch of gas burner switching to get the exact BTU needed on the fly.