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Control electric water heater or use tankless for best efficiency?

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    i have had both in places i lived, Tankless is the way to go simply you NEVER have to worry about running out of hot water oe with a tank and HS, worrying about needing an unexpected bath or shower at an odd hour, plus the energy savings. ( Sorry, there are a few things that even HS cant improve on )
    detail of setup in profile. Link to videos of my projects there as well. Over 300 scripts running every min and counting


      Energy source (gas versus electricity) should be distinct from the tank / tankless approach. Yes, the cost of a BTU to heat water may be different between these two sources in different markets, but the cost of upgrading your gas or electric service to support a water heater might overwhelm that.

      We have a Rinnai gas heater, which the previous owners installed in an exterior wall of the garage to replace an electric water heater located in the furnace room (where there was also gas service for the furnace). But the Rinnai consumes an astonishing 199K BTUs / 199 CFH, which is greater than the rated gas flow through 3/4" pipe!

      Our current gas bill is $18.75 for a summer month when it's unlikely that the furnace came on (we have been using some air conditioning though!). But that includes a $10.29 "basic charge" for the connection. The actual usage is $7.29, and that's for hot water for 3 long showers per day, dishwasher every other day, and a few loads of laundry. Honestly, our cost of heating water is so low that it's not even a consideration.

      What is a consideration, though, is that the run from the garage to the kitchen is rather long - maybe 25' longer than from the furnace room - so I added a 2.5 gal Bosch heater under the kitchen sink (and the electricity for that is not included in the calculations in the above paragraph). And we are remodeling the master bath that is located above the garage, so I had a plumber home run new supply lines from there to the Rinnai to shorten the distance. I'm sure that will lessen the amount of water run in that bathroom in order to get hot water - and that's a double savings because our sewer cost is based on water consumed.

      While I appreciate the low operating cost of the Rinnai, I'm also quite happy that the water heater is effectively outside the house. I've had a water heater fail and leak inside a home and it wasn't a great experience - and as far as I know, water heaters are still not considered leak-proof.


        Tankless Water Heater can be great and you can enjoy constant supply of hot water.