Vent question
Background info - a lot of things around my house were done by "D I WHYYYYYY" (and many obvious ones were missed by my pre-purchase inspection; I was out of state for the inspection unfortunately so no oversight there) and I'm constantly discovering them and fixing them. Here's the latest problem, that I think needs fixing, but HVAC is my biggest blind spot....
This photo is the water heater vent, it is joined by the furnace vent coming from the left and together exiting through a wall apparently up to the roof (I'm going to scope it to be sure it's connected and clear).
I have never had a standard carbon monoxide alarm go off near here. I recently put a reader (for lower levels) in this room, a month ago moved it to right on top of the water heater. Last night with the furnace running it briefly detected up to 28ppm CO. I expect this is from furnace exhaust gas leaking down through the gap at the water heater vent connector.
Is this whole situation (the two exhaust pipes joined) a terrible idea?
Should I remedy it (idk how other than adding another pipe through another hole in the wall) or just keep the monoxide detectors working and wait and see? :/ (I do not like the idea of any monoxide)
Thanks!