Berlin wrote:well, I disagree lisa. Regardless, what the OP's trying to do will cause no fire hazard or risk of loss. It can be done safely without blindly following code.
Ok. why are we still discussing this? We have different points of view, big deal. I thought the idea was to hear all the options. It's not the first time people disagreed with me nor will it be the last. Being different makes the world interesting. Take care, Lisa
It can be done safely if nothing goes wrong. Things always seem to go wrong. Insurance companies are not going to gladly pay out a claim without an investigation. And they are looking for any reason to say it's not covered. I wouldn't be so worried about a fire from the shared flue proposed as much as I would spilling flue gases and CO in the event the chimney becomes somehow obstructed. The boilers draft hood would be the easiest way for flue gases to escape in that case. Also as already stated, that vent is too close to the wood above.
I assume you are talking about a stoker boiler? Once you start using it you will very likley find you don't need to keep the propane boiler running. Why not just disconnect the propane boilers vent pipe and turn off the gas? If you are going away, turn off the stoker and reconnect the propane boilers vent pipe. Unless you go away alot, no big deal, 5 minute job. You don't need a power venter and you won't gas yourself.