H2O heater flue

[allseason]

Is this a legal setup, the water heater flue is straight up into he boiler flue, which continues into the masonry chimney.

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[rkenney]

Sure looks 'jury' rigged to me. The lack of a bonafide coupling betwen two dissimilar sized pipes makes it 'un-approved' to me.

I believe the smaller appliance (water heater) joins a shared flue (chimney) above the larger furnace - for draft reasons.

[Inspectorjoe]

Yeah, that's wrong. Assuming the sizing is correct, using a proper wye, you could run the water heater into a vertical vent from the furnace. But since there is a chimney, the water heater should vent directly into it, above the larger vent from the furnace, as Bob said. At least that's my take.

[SNations]

Aside from the lack of a proper T- or Y-fitting, I don't think there's anything wrong with this setup. Now, I have no idea and no way of knowing if the sizes are proper. But the configuration is OK.

According to the International Residential Code section 2427.10.4, "Two or more appliances connected to a single vent": Where two or more vent connectors enter a common gas vent. . . the smaller connector shall enter at the highest level consistent with the available headroom or clearance to combustible materials.

But that's not the case here. There aren't two connectors entering the vent. There are two connectors combining.

According to section 2427.10.3.4 "Common connector/manifold": Where two or more gas appliances are vented through a common vent connector or vent manifold, the common vent connector or vent manifold shall be located at the highest level consistent with available headroom and the required clearance to combustible materials and shall be sized in accordance with Section 2428 or other approved engineering methods. "

The code is silent on how the common connectors meet up.

I know that there is a Dura-vent installation guide that says that vent connectors from multiple appliances, installed on the same floor level, may enter the manifold from below or from the side of the manifold.

According to that standard, this installation seems OK.

[Marc]

06' International Fuel Gas Code:

502.2 Connectors required. Connectors shall be used to connect appliances to the vertical chimney or vent, except where the chimney or vent is attached directly to the appliance. Vent connector size, material, construction and installation shall be in accordance with Section 503.

Not sure if this applies to residential, since it's from the IFGC.

Marc

[allseason]

I looked up the AO Smith install guide for venting. It shows this arrangement for a manifold with multiple water heaters. The only mention of different sources (furnace, boiler, etc.) pertains to different fuels. This looks like a manifold.

[Neal Lewis]

Yeah, I've seen that arrangement with a manifold in a lot of converted older buildings in Hoboken.