On Aug 10, 7:36*am, Randy333 wrote:
On Mon, 8 Aug 2011 13:34:41 -0700 (PDT), engineman

wrote:
I have to replace my water heater because of an unrepairable leak in
the gas valve.
I have a tank-type heater and am thinking of replacing it with a
tankless.
One problem is that my present heater has it's water connections at
the top and the tankless at the bottom underneath.
To make installation easier I'm thinking of using *flexible
corrugated *copper tubing similar to what is used for gas lines.
I'm wondering if I will run into any problems with this, such as
galvanic action, also will the corrugations restrict the water flow
too much?

Engineman

I just replaced my gas water heater after 23 years. * Tankless too
exspensive. * Went with another tank style. * Tankless also have a
limited temp rise, so if you got real cold water goingin you might
only get warm coming out. *All depends on input water temp and flow
rate. *IE how many people are using hot water at the same time.

Copper to steel is not that bad in my experiance. * Just as long as
there is no aluminum in there anywhere. *My old and new tank style
heaters have galv. steel nipples pre installed that connect to copper
pipes. *They have plastic liners in them and I guess that makes them
"dielectirc"

Remove 333 to reply.
Randy

The corrosion you'd get all depends on what the water itself has
dissolved in it and what stray currents you have running through the
piping. Last water heater I replaced, the new one had dielectric
couplings built in, was a Sears. Rigid copper runs from tank to iron
in the wall.

The thing with Sears is you can usually get parts, that gas valve
SHOULD be replaceable, I can remember replacing my dad's whole heater
when I was a kid, ran about $79, this one was $379. This was slightly
fancier than that one, has a pushbutton piezo ignitor, but basically
the same type of unit.

The one he replaced that old one with was one of those condensing
units with fans and a digital controller, no chimney needed, just a
small hose for a vent. Ran several grand installed, wasn't
significantly better at heating water than the oldtimer, lots more
noisy and took a lot longer firing up due to all the fans having to
run in sequence before lighting off. You can run a pilot light for
years on the cost difference.

Stan