We have an Amana 80 furnace with two associated external vents. One goes to the cold air return.

The second just goes outside and ends next to the furnace without attaching to anything.

Can either of these be blocked on the outside without hurting furnace performance?

We are concerned that mice may be getting into the house through these vents.

Thanks

No don`t close off,, you might put a makeshift screen over the ends,so nothing but air can get in
But you will need to watch it closly to see it doesn`t get stopped up

no don`t close off,,,,,,,,,,you might put a makeshift screen over the ends,so nothing but air can get in
but you will need to watch it closly to see it doesn`t get stopped up

Wmproop- Why is the external vent that is not attached to anything needed? Our house is definitely not airtight, so plenty of air is circulating in the basement as well as from the vent that goes directly into the cold air return.

What danger is there in eliminating that go no where external vent?

Thanks for your prior answer.

John

The factory engineer designed the furnace to opperate more efficiant by needing and using an outside air supply so that there is plenty of air for the induction motor to use. Not being an engineer to explain better ,all I can say is if they didn`t think it was necessary they wouldn`t have required it it be there. Also I really think it is supposed to be hooked up somewhere ,like maybe into the top of the furnace on opposite side of where the exhast vent is coming out of the furnace,but would need to be there to take a look