RW> They only heat water so many degrees above ambient.
TH> Ambient what? Air, water input? You neglected to say. They
Ok I didn't specifically say but I thought everyone
could infer that I meant the ambient temp of the water
from the structure of the sentence.
TH> However, if the flow is low enough the outflow will achieve
TH> a given temp and a gas will be moderated to limit the
TH> maximum. However, if the flow is high (like fillig a tub AND
TH> running a dishwasher) the outflow temp will drop quite a
TH> bit, even to the point where the 'hot' water is merrely
TH> warm, or even tepid. I think you pretty much know the
TH> basics, and these heaters are rather basic.
The way I understand them the output flow and temp are
restricted.  IOW, if you tried to take a shower and
fill the washer the water would be the same temp you
would just have less of it and therefore less pressure,
just like in a tank system.  Of course that's assuming
that the system is set up to supply the max amount of
hot water @ max temp.
RW> They will save money and fuel but they are expensive. The last
  > time I checked one large enough to handle my needs was over $800.
  > IMO, they only are a good buy if:
TH> Wow! When I bought my Myson it was about $350. I was
TH> considering replacing it with a larger unit. But after
TH> seeing the price, I decided to build a solar batch water
TH> heater. It raises the input temp of the water such that I
TH> can get much more and hotter water.
Too much trouble!  I have too much to do through the
day now without having to worry about with: the kids,
dogs, cats, horses, fence repair, car repairs,
cooking.....  Back in my younger days the money savings
might have out weighed the inconvenience but not now.
TH> It turned out to be a far better investment. In the winter I
TH> get more hot water for the same amount of gas, and for
In the winter I spend my time chopping holes in ice on
the ponds for the critters.
TH> Solar is cheaper, you just have to live where the sun
TH> shines.  
From you origin line I'm assuming that you're in CA.
Without trying to start anything I'll just say you can
keep the whole state for several reasons.  One, I'm a
'cold' person.  Heat kills me.  Two, I love having four
distinct seasons.  Three, the politics out there are
too much for me.  Too much government interference in
what I can and can't do.
                      Remember:  Freedom isn't Free!
--- timEd-B11
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