Wayne Whitney wrote:

Hello,

I've settled on getting a gas tankless water heater (no need to rehash
the tank vs. tankless discussion). I realized that the place I want
to mount the tankless unit inside the house is on an exterior wall, so
I could just mount it on the outside of that wall. Is there a
downside? I'm in Berkeley, CA, so it doesn't freeze here. The upside
is simpler venting, and no need to get a sealed combustion unit (a
requirement in my mind for an interior unit).

Cheers, Wayne


We just did an exterior install last week and I found it to be
much preferable to the interior installs that we have done.
The unit that we installed has a thermostat that detects
exterior temps and automatically comes on long enough to
prevent freezing of the unit. This does not apply to the
piping going to the unit, but the unit itself was protected.

The entire cost for venting of the unit was reduced to a $40
stainless steel vent cap that fits right onto the unit.

Minimum clearances from combustables was easily determined by
the documentation and easy to comply with.

I would mount the unit as high as you can to avoid grasses and
weeds from growing into it, but other than that, I cannot see
why the unit should be taking up space inside when it works so
well outside. Easier to service if it ever needs it.

The unit we installed even had a remote thermostat (purchased
sepearately) which was mounted inside the home which allows
the owners to change the temperature setting of the unit
itself without having to go outside.

This is the unit that we installed:

http://www.plumbingstore.com/takagi_tk2_tankless.html

Good luck,

--
Robert Allison
Rimshot, Inc.
Georgetown, TX