brcase
En-Route
This is what I did (Bosch 2.5 gallon, under the kitchen sink) I got tired of running the water for a full minute to get hot water. I have it plumbed to the hot water line from the main water heater, so by the time I use the 2.5 gallons I am getting hot water from the main heater. But I very rarely use that much water at one time, so it doesn't work very hard as it pretty much just keeps the already hot water available at the sink, and rewarms the water that has cooled between the main water heater and kitchen.They make mini electric tanked heaters for exactly this. A tank would require a lot less demand on your electrical system. On demand electrics can really draw a lot of amps.
Brian