Another HVAC problem

Old 10-09-02, 12:15 PM
Visiting Guest
Posts: n/a
Another HVAC problem

I turned my heat on yesterday for the first time this season and I noticed that a strong flow of heated air was escaping from the dilution air vent cover, rather than drawing air into it. The furnace shut down a few moments later.

Is this a clear sign of a blocked flue vent?

I wanted to ask before I climb up on my roof.
Old 10-09-02, 12:38 PM
Ed Imeduc's Avatar
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,386
Received 1 Vote on 1 Post

Need more info. what year is it do you know. A 80 or 92% AFUE
Do you have a flue clean out? Is the water heater on the same flue?
Old 10-09-02, 12:43 PM
Visiting Guest
Posts: n/a
The water heater is not on the same flue.

There is no flue clean out. The flue is completely encased in brick from the outer wall to the roof. Inside, just a duct from the furnace to the inner wall. I could disconnect the flue duct at the inner wall entry point and see if I can detect sunlight, I suppose, before I climb the roof.

The idea of a blockage occurred to me after I felt the rush of hot air from the dilution vent. I'll have to check on the year, etc. but the dilution vent is just a flap that I can easily push in towards the flue duct. It is being pushed out by the escaping hot air at this point.

Make any sense?

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: