One vent blows cold

[kearu]

I have a TRANE heat pump that is about 3 years old, the ductwork was all replaced/installed at the same time as the heat pump. Recently, I noticed that one of the vents is blowing cold air. The vent in the next room, less than 2 feet away, blows nice and hot. Why would this be?

The air handler is underneath the house along with all the ducts and the returns in both rooms are below insulated windows.

[HVAC Pro]

Could be disconnected, or uninsulated.

[trane]

There is a good chance that duct has come apart under the house and your getting crawl space air forced out of the register. Have someone check under the house to make sure everything is connected and sealed.

[kearu]

Thanks, I'll do that.

[mike d373]

Are you sure it's not sucking cold air. It sounds like a return keep it clear. I find too many customers covering returns because they think they are blowing cold air.