The Gaming Den

I'm stuck with this horrible water heater that keeps failing one way or another and so I decided to break the bank buying a new one.

It says it needs 'Sealed single wall stainless steel' for the vent flue. It says not to use Type B venting. I have type B venting and can get type L venting. What type is it asking for?

Ugh. I think I'm going to use Type L and live with it until I can get the real chimney fixed...

-Crissa

Both B and L vent pipes are double-walled. B-vents are intended for use with lower-temp stuff, L-vents for higher-temp. L-vents should do fine if you connect them right, but you don't want to fuck that up because it'll leak carbon monoxide if it can.

What kind/model of water heater is it?

What's wrong with your chimney? If it's not lined or venting properly the exhaust gas will corrode the mortar in the bricks in the interior. Or is it a metal chimney?

The chimney is a brick one built in 1945 and only barely repaired since. It has suffered fairly severe earthquake damage but never actually fell down. Most recently it was given a metal sheathing, which failed at some point and is now loose. It is not in use currently, but we'd like it not to be hanging over our heads.

The furnace and water heater are vented seperately, as metal exterior verticals. I don't know why, but the water heater I'm taking out has a 4" galvanized flue inside for the horizontal, and type B outside.

The new water heater is serious overkill, but it was on clearance and so is the cheapest that qualifies for the energy star label. It's a Bosch 2700ES-LP; I would prefer a Bosch 1600H-LP but they just aren't currently available and aren't energy star certified (even though they're technically better) so don't qualify for rebates.

-Crissa

B on the outside is fine, its only a problem inside where it'll leak.

That galvanized pipe is basically what you're going to get for the single-walled stainless. At 4" I think it'd serve your model too if you can seal it right... but again, don't fuck around if you're not confident due to CO leaks.

It says not to use galvanized, and use stainless instead. We found a stainless kit by the hot water heater maker hidden in one of the local hardware stores warehouses, so I have a section of stainless (supposed Z) chased with a section of L now.

The plumbers who have used the system say that it's their favorite, except when the pipe has condensation issues. I suppose I'll put a condenser unit on order and re-do the exhaust when it arrives.

Right now I can get L (which has the same stuff inside that the Z does) on deep discount therefore the Z just isn't cheaper. Also, I'm not hot on the idea of hot single-wall flue running through the crawl space of a 1945 redwood cabin...

-Crissa

You have to maintain clearance by code regardless, but yes, being worried about wood and heat in close proximity is the right thing.