Inadequate Elevation?

[Dan Cullen]

33064

Is the metal exhaust termination inadequately elevated above the chimney crown? Does this pose a risk for poor venting of the WH/Furnace combined vent? Thanks!

[Bob Harper]

Appears to be B-vent used to reline a masonry flue, which is ok in and of itself. However, it should have been extended well above the fireplace flue so heater flue gases cannot recirculate back down the fireplace flue into the home. It should have some means of a top support and storm collar.

The concrete crown is badly corroded and spalled by the acidic flue gases. It needs to be resurfaced or coated.

There does not appear to be a proper expansion joint between the crown and the fireplace flue tile, which should only extend 2-4"

I'd also pressure wash the top of the chimney as needed then treat with 100% vapor permeable water repellent once all repairs completed.

There could be some adverse wind effect created by turbulence from the fireplace flue depending upon wind direction.
HTH