Thread: Can you run a condesing furnace exhaust vertically

Can you run a condensing furnace exhaust vertically

Yes. As always with condensing furnaces, proper managing of condensate is very important. A vertical exhaust pipe will certainly allow the condensate to drain back to the condensate management system at the air handler.

When condensing furnace exhaust pipes are run in a more horizontal manner, the pipe must always slope down hill towards the furnace to allow the condensate to drain into the condensate removal system.

Running the furnace vent vertical isn't a problem.
In this case the problem is the way it was run.
- Top of vertical vent pipe open, no 90, in this type of install you need a Tee at the bottom with a drain hose to deal with water coming down the pipe
- top of chimney not properly terminated, this is going to let rain water and snow into the home
- top of chimney not properly terminated which will allow premature erosion and repair costs
- top of chimney and chimney in basement not sealed at all, this will allow cold air drafts and critters into the home increasing energy costs
- the mound of mortar should not be seen as a proper chimney cap, as evident by the algae growth already