On Mon, 26 Nov 2012 05:29:20 -0800 (PST), "
wrote:



Â*Chimneys cool off fast in winter.
That's why there are few unlined chimneys left.
Talking about NG only. Â*Haven't had coal or oil in decades.
Condensation talk is to sell liners to those who don't have them,
or to now sell a hi-efficiency water heater with a dedicated vent.

You're obviously an idiot. Condensation is a real issue.

So is the hole in the ozone layer. And global warming.
As expected from you, you can't keep up. Water heater flues flow into
cold chimneys all winter. Sunny days can keep the furnace off for
hours. Chimney is cold. Water heater lights up.
Happens all the time, and has for ages.
Deny that all you want.
Most chimney flues are lined. Mine is lined with SS.
Also has a condensate drain.
That should be addressed when replacing/upgrading a furnace.
Had mine installed 17 years ago.
I call that "home maintenance." Wasn't required by code.
Chimneys are not collapsing all across the country from acid corrosion
or freeze/thaw spalling. A furnace and WH are independent actors.
Always have been.

There are codes that specify the size of a chimney for the
particular appliance. You can't just vent any size appliance
into any size chimney. There is a max size allowed.
It's like saying the issue of putting a 20 amp breaker
on 14 gauge wire is just to sell breakers.

No sense at all there. Chimneys don't work by electricity.
Codes were/are written for furnace/WH running, furnace only, WH only.
Remove furnace or WH from the stack, and the other works just fine.
An old house with chimney venting installed before codes, or adequate
codes, should face the local inspector.
Probable worst case is you have to install a liner, Because of draft,
not condensation. CO is the big issue with an over-sized chimney.
You're a cracker-barrel type guy, and a good target for salesmen.
That's okay. Takes ll kinds.