"B" Vent Question

SteveSmith98 · 01-01-2009, 10:31 PM

Hi,

I have a hot water heater, and a furnace both running on natural gas. They both vent through the same chimney. A while back, the water heater was replaced and the vent from the water heater to actual chimney was replaced with new "B" type venting. I was told this was code requirement and I had no choice.

I have two questions:

1) The furnace vent joins to the hot water vent at a Y junction. Right now, the Y lies flat. Is that a requirement? I'd like to rotate the Y so the furnace vent joins in from underneath so I can move all the ducting closer to the wall, where I'll hide them.

2) The "B" venting has instructions on it that say not to use screws at the joints, or "anywhere penetration is possible". However, at all the joins, I see screws were used to fasten them. Was this installed wrong? I believe the "B" vent is to reduce the chance of carbon-monoxide escape -- so is this dangerous? Should the joints be taped, and with what? Does this meet code (I live in Ontario, Canada).

I've attached some photos showing both the Y and parts of the vent where screws were used.

Thanks!

**Termite** · 01-02-2009, 12:01 AM

Type B vent has two walls, an inner and an outer with an air gap in between. I see no problem with screws as long as they are short enough that they don't penetrate the inner wall. Back one out and shine a light in there to see.

The current installation of the Y fitting looks good and I wouldn't change it. I'm unaware of anything that would prohibit its installation with the Y leg hanging down as long as you still have plenty of slope upward on the appliance vent.

Chemist1961 · 01-02-2009, 08:11 AM

With what happened in Woodtsock I think we're all being cautious. I have similar mid efficiencey setup but the standard, not dual wall for my vent. My water heater was upgraded several years ago. The hot water exhaust enters just under 90 degrees. I believe our codes here in ON are more easy on retrofits versus new construction but your gas company may have some info as well. If you tape, use foil. HD has the big roll for about $10 and another same size for $14.

Chemist1961 · 01-02-2009, 08:18 AM

Steve,
I don't think the hydro inspector would be happy with that wire hanging across your gas line and vent pipe. There is a code issue there for sure.

The other Steve

SteveSmith98 · 01-02-2009, 09:12 AM

Chemist1961: If you're talking about the white 15A 120VAC wire -- that's the power feed to Air-Conditioner. The installer did a sloppy job on that all around (before I bought the house). I'm looking to do a rewire of the whole basement, which is when that detail will be cleaned up.

thekctermite: So the vent requirement is a slope upwards towards the chimney (seems obvious). I was worried if I have the Y leg down, then it would facilitate condensate and water runoff directly into the furnace (mind you, with the way it's setup now that's probably what would happen).