[SustainableTompkins] hot water heaters

[ejgeorge at riseup.net]

Hi.

We have a Takagi TK Jr. and think it's great. Yes on the couple  
seconds longer for hot water to arrive. Ours is a "Jr" which means  
it's really meant for cabin size but without any intentional planning  
on our part our hot water demand has only exceeded it once in four  
years (shower, tub, washer, and dishwater all at once -- the water  
went lukewarm...a lot nicer than the freezing blast from an emptied  
conventional tank!)

Couple of things to look for:
ignition options that I'm aware of are pilot (least efficient), spark  
(more efficient but won't work when electricity is out), and  
hydro-ignition (energy from the running water actually sparks the  
ignition - a little harder to find, last I checked a bit more expensive)

another nifty feature is thermostatic control. If there's a likelihood  
you might preheat your water (e.g. from solar or wood stove) this  
adjusts the heat or water flow (not sure which) so that it is only  
heated to a certain temperature (such as 120 degrees). The standard  
models just automatically heat the water by a certain amount (assume  
your incoming water will be underground temperature, or ~50 degrees,  
and therefore raise it by 70 or 80 degrees as it flows through - which  
would be a problem if you had already preheated it to 80...)

For the distant faucets you can also get little booster units that  
heat the water at the faucet until the hot water arrives. I think  
they're called something like chile peppers?

ej