Tankless water heaters make sense if you have frequent high demand or heavy demand at certain times but not much usage at other times. These heaters minimize heat loss through the insulation as occurs on standard tank type heaters. There is almost no standby loss with tankless heaters. But to increase your wiring from 4.5 KW for tank type to 36KW for tankless requires serious thought. This wiring often is larger than the whole house panel wiring for older homes. If it were me and I wanted to stay w/ electric water heating, I would replace with a tank type w/ 2 in. of foam insulation and over-insulate with a blanket kit to minimize heat standby loss. One major manufacturer of hot water heaters, both tank and tankless, states that their research has found that there is little difference in annual energy savings between the two for most residential users. If so, why pay the additional initial cost?
Good point on the insulation. Our home is 25 years old... how do I know what size wiring we have now in KW (that's different from the amps listed in the breaker box, right?) - Is it written somewhere on the wiring to the HW heater? Or on the wiring to the stove? Or does one tell by size?
We're only two here and don't use that much hot water - and the dishwasher heats it's own. There's tax credits for gas ones, but we'd have to have a gas line run - and the unit would have to be outside. But, we're in Virginia, so it doesn't often get real cold.
So, no one has used a Stiebel-Eltron... and the prices (I see from the link, thanks!) have come down on Bosch and others that Lowes carries. Wonder if there is still a tax credit?
OK... I'm just muttering to myself now, but if anyone has answers, I welcome them!
We have a 100 year old house with five bathrooms and other plumbing needs, laundry, kitchen etc., spread over 4 floors and 4500 square feet. Is it possible to use an on demand water heater or is the distance that the heated water will have to travel too far to stay hot, thereby making the on demand system a poor choice for our home.
The travel of the on-demand shouldn't be any different than what a tank has to travel.
But, with on-demand, you can use more smaller units closer to their use point with on-demand without having to install smaller tanks at each location.