On Sun, 7 Sep 2008 17:33:07 -0600, "Bob" wrote:

My house, built in 1956, needs a new heating system boiler. It's as old as
the house.

I've seen some models that have domestic hot water (DHW) capability - are
these worth getting? It seems to be a waste to turn on a boiler rated
50,000-250,000 BTU for hot water in the dishwasher.
I set up a hybrid. My tankless coil in the boiler was being out paced
by the kids showers once they got into their teens. I had an electric
HWH installed in series with it. During heating months, my boiler
preheats the water going into the electric heater. In the summer, no
gain.
As an aside at installation, I had the plumbing for the HWH done so
that I cn also cut it out of the system, and revert to the boiler
only.
The boiler runs on 120V, the heater on 220. My generator can carry
the former , but not the latter. So, when a storm like Hanah disrupts
my power, as it did, I can simply cut the 220 off, cut the heater out
of the system, turn on the boiler and take a shower. Really
appreciated when one comes in from sorting out the downed tree,
powerline, cable line, POTS line mess.
BTW, in case you hadn't thought about it, if your POTS line/DSL line
is ever parted, you can simply spice in a length of outside telephone
line to replace to connect, tape it up and leave it lying on the
ground until the phone company gets around to repairing it. Did that
too, and it will last until VZ gets their line to the house back up on
the house/pole.