Calling all HVAC pros

[jjohnsonElknewbie]

Hey guys, a couple years ago I put a steel roof on my house and had them remove the old chimney in the process as my furnace has a power vent. My HVAC guy re-routed the furnace exhaust pipe horizontally out the north side wall (3"or 4" b-vent). Ever since, I've had trouble with the furnace getting blown out by strong NW winds. He said there wasn't much to be done and to try putting a box or barrier in front of the vent. Done.

Last winter the draft inducer motor went out and I replaced it. The new unit is an upgrade from the 1999 OEM version and seems to push more air. However, I'm still concerned about it getting blown out this winter.

So the question is, what is the most effective high wind cap for horizontal b-vent?

 

[Jstumbaugh]

Duravent high wind cap is pretty solid. Your furnace is prob 4".

 

[jjohnsonElknewbie]

Duravent high wind cap is pretty solid. Your furnace is prob 4".

Thank you for the recommendation. It has the Amerivent model that looks like this now. Does this change your suggestion at all?

 

[Jstumbaugh]

I'm surprised that you are getting that much "blow back" with that topper,

This is what we sell. Do you have a very short vent run?

 

[jjohnsonElknewbie]

I'm surprised that you are getting that much "blow back" with that topper,
View attachment 460423
This is what we sell. Do you have a very short vent run?

Thanks again man. The vent run is roughly 2.5' vertical off the furnace to an 90 degree elbow. Then approx. 4' horizontal west to another 90 degree elbow. Then it's about 16' north to the exterior wall. Outside there is about 2.5' of pipe with the cap.

 

[Jstumbaugh]

Your vent run isn't short at all. and normally a north wall shouldn't be taking a prevailing wind continuously. Any chance your blocked vent/ pressure switch is weak and tripping prematurely?

 

[jjohnsonElknewbie]

It's possible, I think it's OEM (1999). The new inducer came with new silicone hose to connect to the presssure switch, and I'm hoping that may help as well. I also cleaned the flame sensors with some steel wool.

I had a heck of a time getting the correct inducer motor as well. I finally found the correct Rheem cross reference table, and it could be that I wont have any issues this year. However, I just wasn't sure if there was a better cap out there for this application. The one you suggested is pretty cheap, so it can't hurt to replace it too and see what happens. First big cold front of the season coming today and our highs will be in low 50s tomorrow with low in the 20s. If we get wind to go along with it, I'll have my answer soon enough!

EDIT: the cap you suggested says only applicable to vertical terminations, darn it.