On Sun, 27 Apr 2008 16:53:25 -0400, "Art"
wrote:

We just replaced a direct vent tank with a tankless. I did it because
replacement direct vents run an unbelievable $1500 with labor and a 6 year
guarantee tank. The tankless should last 15 years at least. It cost $3k.

I had it done by gas company expecting a perfect job. It was perfect....
the second time they did it after I bitched.

Tons of things can go wrong. Gas pipes have to be big enuf. So does meter.
Then the plastic pipes they used had smaller internal diameter than CPVC I
had before. They replaced with copper the second time. Then the exhaust
should be slanted down unless they is a condensation collector. Mine was
pitched up the first time.

After it was reinstalled correctly, I can say it is decent but not as good
as a tank. It is slightly slower. Also my basement is much cooler now in
the winter (an advantage in the summer) but cold water is now much colder
and that makes hot water seem to take a long time to flow.

Overall stick with a tank.


For some reason, there is a myth that the "tank" systems are horribly
inefficient and wasteful and that the "instant tankless" systems are
green and more economical in the long run.

For most tankless installations, by the time you get through paying
and solving all the problems, the payback period is going to be a long
way off in the distant future.

Last time I thought about my gas heater tank (I think that it's a
great thing that I don't have to think about it much), the pilot light
has never had to be relit in 10 years. It's like the eternal flame!

In the United States, the "tank" systems are a tried-and-tested
commodity item (in most cases) and can usually be replaced in the same
day at low cost. They last for years and the lifetime can be usuallly
be extended if you take care to flush it and replace the electrode at
periodic intervals.