I did something similar in my DR, for about the same reasons.
We have a tankless heater for the house, but for washing and such in the DR, the demand is smaller than the tankless's minimum flow, so it doesn't come on at all.
I've installed a 2.5 gallon point of use heater under the DR sink which is fed by the hot water line. When my flow is high enough, it gets pre-heated water from the tankless. Otherwise it takes care of the low flow situations.
It's nice to turn on the hot tap and have heated water within a second or so.
A 10 G heater would probably work well. I do run out occasionally if I'm using a lot of straight hot water like for rinsing big trays. The 2.5 gallons doesn't last long and the tankless gives a slug of cold water every time you turn the water off and on again.
Last edited by bdial; 05-17-2011 at 06:04 PM. Click to view previous post history.