* Nigel wrote, On 6/19/2007 2:27 AM:
I've just installed a 65lt hot water tank, it has 2 heating coils and an
immersion. I haven't got around to connecting the 2 heating coils so for now
it runs on just a 1 kw immersion heater... I connected up my 1.2kw
generator ( just a cheapy from B&Q, not a marine genset) and it took 2 hours
to get warm and about 3 hours to hot.... For no very good reason I had
thought it would heat in about an hour. I have tried looking up calorific
values of water etc, but just got myself confused... anybody here shed
some light for me..


I'm not sure if this applies to your setup, but here's a couple of
things I learned from mine: First, my water lines go up from the
engine to the H/W heater, allowing for the possibility of an air
bubble at the top, reducing flow. If possible, this point should be
accessible to purge the line.

Second, although the water is well heated when the engine is working
hard (11 gals heated to 150+ easily in under an hour - if its already
warm it only takes 20 minutes to get hot) when the engine is used for
battery charging it never gets quite hot enough, and thus never quite
does the job. Fortunately, in the summer "warm" is good enough.