2014 32BUDS - Heat being pulled through return vent while AC is on?

[Ranchdip]

While running my AC I'm getting heat pulled through the vent as shown in the picture. I pulled the vent cover off and could not determine actually where the heat was coming from. The gas was turned off so I know the pilot wasn't lit. Also, I'm getting a septic order there as well. (I recently discovered a small leak in my grey or black tank plumbing somewhere.)

Any thoughts where the heat is coming from? I'm assuming the odor is from the small leak. I'm guessing the heat is from the convection or heat being pulled from the under lament under the camper because of the temperature differences in the camper.?? I had the camper AC set at 71deg with an outside temp of 85deg.

Any thoughts?

Thanks!

 

[bigdob24]

That looks like the cold air vent for the furnace. It draws air in when the furnace is running.
I have no idea why there would be hot air coming from it unless there is a break or crack in a heat line and its sucking warm air from the basement or underbelly when the air is on.
Make sure everything is connected to the furnace plenum as it should be.
good luck figuring this one out

 

[fredwrichardson]

While running my AC I'm getting heat pulled through the vent as shown in the picture. I pulled the vent cover off and could not determine actually where the heat was coming from. The gas was turned off so I know the pilot wasn't lit. Also, I'm getting a septic order there as well. (I recently discovered a small leak in my grey or black tank plumbing somewhere.)

Any thoughts where the heat is coming from? I'm assuming the odor is from the small leak. I'm guessing the heat is from the convection or heat being pulled from the under lament under the camper because of the temperature differences in the camper.?? I had the camper AC set at 71deg with an outside temp of 85deg.

Any thoughts?

Thanks!

View attachment 37074

The AC has both output and intake up by the AC. If you are pulling air from the furnace return vent then you have a negative air space meaning the AC is doing a better job of removing hot air than imputing cold air. If the outside air is 85 degrees and the inside air is at 71 degrees and you were pulling air from the basement then that air would seem to be warm. I would open the front door or windows and see if you are still getting warm air from the furnace vent. If the warm air stops from the vent you either need to check the AC filters or AC vents to see why it is pulling more air out than putting air in or you need to seal the basement area so that no outside air can enter from the basement.

 

[Ranchdip]

Great info guys thanks.. I'll check the furnace plenum. Is there a duct that blows into the underbelly? IS that typical for North TRails? Thanks

 

[Garypowell]

I think Fred hit the nail....but wanted to add my experience. For one thing I am not sure if I can tell from your picture if you are ducted or not. If you are then you might have a leak somewhere in your duct work.

I was concerned that every time I removed a light fixture from the ceiling cold air came out. I then sealed the ends of the duct (my model has two) at all four ends right after the last outlet. It did seem to help.

If you are not ducted you might want to get up on the roof and pull your outer cover off and make sure the cold air system is isolated from the outside air.

As Fred pointed out....if you have air escaping outside of the unit it will cause a negative pressure inside....and we know nature hates a vacuum....and it will pull in air from anywhere it can.