Enbridge Vent Connector issue

[scarey8]

I have a situation with and Enbridge inspector regarding single wall vent connectors on Category 1 unit heaters.  Newly installed Cat 1 heaters located with minimal lateral vent connector lengths, transition to B vent and up through the roof.  Appliance is certified for use with both single wall or b vent as a vent connector. 

Enbridge inspector detailed that C vent for vent connectors is not permitted and will result in a red tag as B vent is the safer option.  This obviously resulted in an "exchange of opinions".

No where in the code can I find a clause which details this scenario, if C vent / single wall vent connectors weren't allow, why would table C.2 exist?

Codes being enforced by the "authority having jurisdiction" are hard to navigate when inspectors expect contractors to know their preferences. 

The inspector also detailed that he requires a gas pressure test tee installed immediately downstream of a system or appliance regulator. Which I agree with and have already installed, but the inspector says the branch of the pressure test tee be fitted with a ball valve for ease of pressure testing and adjustment.  That is no where in the code book, so I'm suspicious of this inspector is just out to make a statement and change the world. 

[Admin]

Some appliances, like natural draft water heaters are still allowed to be vented with single wall vent connecters.

This isn't very clear in our Gas code and Table 8.5 simply lists a special venting system for Category I and Category III appliances.  Horizontal venting should be stainless steel but in your case B-Vent should be sufficient as the appliance is vented vertically and defined as Category I.

What is the model of the unit heater?

I have never heard of any requirements to include a pressure test tee or shut off valve for that purpose.

[scarey8]

I do recall the change in horizontal venting requirement being stainless steel for residential, but I was still under the impression that commercial buildings you could still use combination of C and Vent, it was a reznor brand unit heater, UDAP series.  I will have to follow up with the actual model number.

6.8.10

A test port shall be installed immediately downstream of a line pressure regulator or a high pressure regulator except where the pressure regulator can be adjusted while measuring and observing the supply pressure at any appliance being served by the pressure regulator.  Where opening the test port could create an uncontrolled release of gas, the test port shall be equipped with a manual shut off valve that is either capped or plugged. 

regulator on roof, unit heaters beneath the roof in warehouse space.  Looks like the requirement is there, heads up to everyone else going forward.

[Porcupinepuffer]

As far as I know the stainless venting is only required on horizontal venting going out the wall in residential dwellings. Commercial doesn't have this requirement for some bizarre reason.
I've also seen a Reznor heater in commercial with B vent going up through the roof and the C vent elbow rusting out pretty good near the unit within a year.

For the regulator requirements, I did have an inspector require the same thing you mentioned, including the valve. I was totally unaware of it as I had seen endless regulators on rooftops with none of these Tee's installed. I figured you'd just make the adjustments over at the regulator based on the test port pressures at the unit.

[Admin]

I believe they ship a specific Vent Installation manual with Reznor.  I attached one and on Page 2 it says,

2.1 SECTION 1 - Type of Pipe
Vertical Vent Pipe - Use Type B double-wall pipe for all installations.
 
Horizontal Vent Connector Pipe - Sizes 30 and 45 require Type B double wall pipe for all installations.
Depending on the installation (Refer to TABLE 1A or 1B), Sizes 60, 75, and 100 may use either Type B double-wall vent pipe or 26-gauge or heavier galvanized single-wall vent pipe

I would say if you have a 60,000, 75,000 or 100,000 BTU model you can use C-vent as the vent connector.  Double check the Vent Manual that shipped with your unit though.

I don't do any commercial but thanks for the heads up about the test port.

[scarey8]

Endless rooftops with pressure ports on combination gas valves for pressure readings don't seem to be the issue in this situation.  It is where the regulator is on the roof of a structure or remote area, and all appliances are else where.  the ability to check the pressure immediately downstream of your regulator.  Like on two stage propane regulators. 

My guess is they are limiting the risk presented by leaving your manometer at a unit heater and going outdoors to increase pressure. 

[Porcupinepuffer]

When I ran in to the regulator T and and valve situation, it was on a rooftop with natural gas and the regulator was about 10' from the appliance on the roof.

[NoDIY]

6.8.10 is new in the 2020 code
A long overdue requirement in my mind. A service techs friend.

Id have a look at the install manual regarding the vent connector.