Quick question - Is there a natural gas tankless water heater that can do
more than 4 gal per min that can vent with PVC horizontally and use room air
for combustion? Am I asking for too much? I am looking to replace a 40 gal
tanked model that uses a 3" PVC power vent horizontally. The 40 gal is just
not big enough for our household and I am considering tankless, esp since
there is a $300 tax credit.

On 2006-01-06, No wrote:

Quick question - Is there a natural gas tankless water heater that
can do more than 4 gal per min that can vent with PVC horizontally
and use room air for combustion? Am I asking for too much?

All the tankless water heaters I'm familiar with are Category III
appliances, which means they use a sealed stainless steel vent.
However, many of them can be vented horizontally. I thought that the
Takagi TH1 might be able to be vented with PVC, since is a condensing
tankless water heater (the only one I know of) , but according to its
installation manual it still requires the Category III vent.

BTW, there are high-btuh condensing tank water heaters, such as the
Polaris by American Water Heater, which can be vented horizontally
with plastic pipe.

Cheers, Wayne