When my new furnace was installed, the vent was put outside the house next to landscaping bushes. It has killed one of my bushes. It used to be vented up to my roof and out. Can I move this outside vent to the roof vent?

  • 3
    Need a picture or better description of what the vent looks like. Is this a high-efficiency furnace with a small (2 inch) plastic vent pipe, or a standard efficiency furnace with a large (4 inch) metal exhaust?
    – Grunthos
    Jun 5, 2014 at 14:23
  • 3
    Consult the manual that came with the furnace. Depending on the installation, you may not be able to. Insufficient information to make any comment as it is not your old furnace. Aug 5, 2014 at 14:26
  • At this point, it might be easiest to just accept that you're not going to have a bush there. You could replace it with a little mini rock garden or something.
    – iLikeDirt
    Oct 4, 2014 at 14:55

3 Answers 3


No, it sounds like you have a high efficiency furnace and these will direct vent outside versus using the chimney stack to vent. You might want to talk to the installer to see if it could be better positioned as to not damage you plants.

  • 3
    My high efficiency furnace vents warm (not hot) moist air. Seems unlikely to kill a bush.
    – Grunthos
    Jun 5, 2014 at 14:24
  • When I installed mine, we did have the option of exhausting up to the roof through the existing chimney... but we would have had to re-line the chimney, since the chemistry of the gas condensing boiler's exhaust is different from that of the oil boiler it replaced. Since I preferred to get rid of the chimney entirely (and did so when I re-roofed), we went with the out-the-side exhaust. Hasn't damaged the shrubbery, but I do need to keep the shrubs trimmed low enough that winter snow won't block the exhaust and intake.
    – keshlam
    Oct 4, 2014 at 16:07
  • 1
    Combustion produces numerous acids which can definitely kill plants; E.g., acid rain.
    – Mazura
    Apr 3, 2015 at 1:20
  • 1
    May be a matter of finding a bush that likes acid soil, then... Mine haven't complained yet.
    – keshlam
    May 3, 2015 at 4:13

I had a "plume diverter kit" fitted to my vent. It is basically a purpose-designed S-shaped pipe that moves the vent further up.

The maximum lengths and numbers of bends allowed depends on the furnace design and perhaps on local code - so you should probably ask the manufacturer or installer.

Note: My experience is in the UK where terminology differs from that used in the US.


The bush is an excellent indicator of how wide this vent's effect is. Put in a new bush away from the vent & leave a gap for the vent or replace the bush with a chair or loveseat, bird bath, sculpture or fountain looking thing. Better than a dead bush. A further assistant to the bush gap above is to have the installer approve shrouding to minimize the bush gap & protect the bushes.

Other than that, yes it can go through the roof instead & again, But, both the intake & the exhaust have go up together. They usually have to work on the exact same atmospheric pressure to operate correctly.

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