Hi,

I have a problem on my second floor. I have a two floor home and my AC is using honey well zoning system and it has two zones. Zone 1 for downstair and zone 2 is for upstair.
I have no problem on cold air on first floor; but I have a problem of cold air on 2nd floor.
I have noticed that the cold air comes out the place where the filter is installed and I thought the air should be sucked in at the place where the filter is installed. When I bought the house in 2004, the cold air in 1st and 2nd floor are coming out very strong; but not any more. I did charge my AC with 4lbs of freon 410 a week ago. About the cold air problem on 2nd floor, the service man said that it might be come from the damper.
Why the cold air comes out the cold air return grille where the filter is installed. I did not see this happens a few year ago.

It is possible you have a damper problem. If you are knowledgeable in that area fix it if not call for ON SITE service.

4 pounds of 410??

Why?
What was your superheat?
What was your subcooling?
What were your suction and discharge pressures?

I mean 4lbs of freon type 410 because service man said that the freon is low. The heat should be ok; I have not tried out until December. For the cooling, the cold air comes out weak; it is not like 4 years ago when I bought the house in brand new; but the main concern is why the heck the cold air comes out from the air return duct; that is really funny. It is supposed to suck in the air; not blow out the air in the return air duct.

Blower running in reverse?

Damper could be stuck.

hvac1000,

I think may be the damper stuck and I don't think it is due to motor running in reverse because my first floor is still working OK. About the damper, I have three damper; two motorized dampers, one for each zone. The other is the bypass damper, which is non-motorize damper and it is for manul adjusting. I think it could be either the bypass damper or the motorized damper for the 2nd zone. For the bypass damper, I don't think it is broken because it is very simple without electronic; but it is needed to setup or adjust right. Right now, I have a problem adjusting it correctly. It could be incorrect adjusting the bypass damper, it could result from the air blowing out of the return air duct. For the motorized damper on the second zone, I did disconnect one of the wire to free the power so that it is in the open state automatically; but that does not help either. Do you know how to adjust the bypass damper. Mine has a metal rod that has a weight on it. I think when the rod is perdendicular to the duct; that mean the bapass damper is in the closed position. As the manaul said, 1) when the two motorized damper are open, the bypass damper must be closed position and 2) when one of motorized damper is open and the other is closed; then the bypass damper will gradual swing to one of the side. Is this correct. My bypass damper works on #1 but it did not work on number #2. Do you know why? Is there a way to adjust correctly?

How do I identify my bypass damper or motorized damper not working?

Watch it see if it is working if not refer to the manual that came with the damper/control assemble. There are way to many damper/control companies that there and no universal way to tell which component is defective without the diagram and a meter.
Note sometimes there is a manual switch to open the damper or you can disconnect the linkage and then open it up as a temporary cure.