Heater Vent Not Blowing Air

I would be remiss if I didn't add something here about it being mentioned having at least one cold air return per floor. I am worried you may have two or more and decide you can cover one of them because there's more than one per floor. If you have more than one there is a very good reason for it which is for optimal efficiency. I've owned a couple of homes that had cold air returns in nearly every single room because of the floor plan. I am reitierating that you really need the existing cold air return(s) and need to keep them free of blockage.

You need at least one cold air return per floor and it sounds like this one is it.

You need to have that air return vent in order for the heating and/or cooling system to work properly. It needs the air flow to run warm and/or cool air efficiently throughout the home and, if you even cover it with furniture, the system is going to come on more often which will cost more money in energy and probably shorten the life of the furnace.

Could that vent be a return vent? As warm air cools and sinks to the floor the recirculating vent would draw the cool air into the vent and be recirculated to the furance, be reheated and sent up the vents to warm the house. Sort of like a hot water system. Hot water is sent through the radiators. As the water gives of its heat, it is recirulated back to the furance and the cycle starts all over again.