Why is cold air return blowing air out and registrars taking in air?

The conditioned air comes into the room, vie a register. The cold air returns take fresh air to the furnace. Depending on the era of your home you heat/ ac might be at ceiling level With the cold air return at the baseboard level.

Ive never understood the logic of it. Cold air sinks, hot air raises. So it’s winter and I’m wearing thermal undies plus 2 more layers trying to keep warm. I did put a small fan pointing to the ceiling to at least move the air arround. It not a warm house at all.

Here are a couple of sites to help you troubleshoot. See if it helps?

https://www.hydesac.com/supply-return-vents-whats-difference-exactly/

https://www.servicechampions.net/blog/5-quick-furnace-fixes-anyone-can-do-before-calling-a-repairman/

Has the system been worked on recently?! The only way this would happen is if someone reversed the blower in the housing or accidentally put the blower back in wrong.

Is this a new installation? It sounds as if the wrong type of furnace was installed. Even if a blower was replaced backwards, it would not do this. Most furnaces have a squirrel cage style fan and a reversed squirrel cage would simply produce no air. There are upflow and downflow furnaces. The installer chose the wrong one. This needs to be corrected immediately.

I got another 2 inches of snow this week.