Settle an Argument Here With GC

[Rick Hurst]

Is this vent approved for use on a water heater or for a furnace?

rick

[Eric Barker]

What vent? That thing is tapered, like a flashing collar. And why would the cap be fastened to the collar? Might there be a vent terminating inside the collar?

[Scott Patterson]

Like Eric said, it might have a vent pipe terminating inside of that cone. What does the manufacturer require? That would solve any argument.

[Jerry Peck]

I am not aware of any vent like that which is approved for use as a gas vent cap - even if there is a single wall vent sticking up inside it.

[Jake Guerrero]

I guess those are more common in this area than other areas. I see these all the time on older homes.

"Usually" there is double wall terminating at the end of the vent cover.

Rick, the only thing I've ever come across (as far as writing) on these was some old CABO phrases which referred to these "bonnet" vents having drafting issues with natural draft furnaces. Of course the furnace or WH manufacturer's instructions would take precedence, the type of house this vent is installed on usually does not have equipment installed that has legible/accessible/complete labeling or instructions on the unit.

Let me know if you find out more information.

[Rick Hurst]

Jake,

How are you doing?

Yeah those type vents are common on many of the older homes throughout the Metroplex. My problem is when the home becomes remodeled and new water heater and furnace equipment is installed, its time to upgrade these type of vents to B-Vents as recommended by the manufacture.

Some of these GC who are remodeling these homes, keep throwing up the old comment about being "grandfathered".

I ask them why they raised the water heater off the garage floor then?

Rick

[Jerry Peck]

I guess those are more common in this area than other areas. I see these all the time on older homes.

I suspect they are common all over as I used to see them on older homes too.


"Usually" there is double wall terminating at the end of the vent cover.

I also saw many with double wall vent terminating into them, and many with single wall vent terminating into them, however, ... "into" is the key word as they are not connected together nor sealed, and much spillage will occur back down into the space below.


Rick, the only thing I've ever come across (as far as writing) on these was some old CABO phrases which referred to these "bonnet" vents having drafting issues with natural draft furnaces. Of course the furnace or WH manufacturer's instructions would take precedence, the type of house this vent is installed on usually does not have equipment installed that has legible/accessible/complete labeling or instructions on the unit.

This is from the old 1994 SBCCI Standard Gas Code: (bold is mine)
- G608.3 GAS VENT TERMINATION
- - G608.3.1 Gas vents shall extend at least 2 ft (610 mm) above the highest point where they pass through the roof of a building and at least 2 ft (610 mm) higher than any portion of the building within 10 ft (3048 mm), except that gas vents need not comply with this provision when a vent cap which assures proper venting is attached to and terminates the vent above the roof. Such vent cap shall be listed or approved by a nationally recognized testing agency and shall be installed according to the listing or approval requirements.
- - G608.3.2 All vents that extend through roofs of houses and buildings shall have a weather resistant flashing.
- - G608.3.3 Vents shall not terminate less than 5 ft (1524 mm) in vertical height above the highest connected appliance draft hood outlet or flue collar.
- - - EXCEPTION: Venting systems of direct vent appliances.
- - G608.3.4 Type BW gas vents serving a vented wall furnace shall terminate not less than 12 ft (3658 mm) vertically above the bottom of the furnace.

I've never see one of those with anything on them which would indicate that they are 'Listed Gas Vent Caps' or anything like that.

[Jake Guerrero]

Jake,

How are you doing?


I ask them why they raised the water heater off the garage floor then?

Rick

Starving....ramen noodles, anyone?


Good point about raising the WH...which they probably only did because the AHJ told them to.