Is this allowed??

Small pipe is water heater flue. Larger one is furnace flue. It there an issue with them being tied togather like this??


The fitting where the to pipes connect does not appear to be adequate, however I cannot see through the pipe.

The main flue pipe (to the roof) must be the size of the largest pipe plus 50% of the second or additional pipes. I don’t see this happening in your photograph.

The pipe from the water heater appears to be single wall. If so, there is an issue with clearance to combustibles.

It appears that the two double wall pipes are not properly seated and locked together. The bottom double wall pipe has a hole cut into the side of it for the other smaller double wall pipe. A no no. And single wall pipe completes the connection. I would take it that this is an unheated attic? Then Double wall pipe, tee and appliance connector must be used. Period.

I second this motion!