I have a hot water baseboard system and it works great except for 1 room. My office which i work all day in. A New boiler was installed in late 2019.

What is happening is that in one room (1st floor) I can feel heat coming out of the inlet pipe but it only makes it about 1 foot past the inlet pipe then it feels cold again. I have tried to bleed the air out at the end of the line but no air comes out just a stream of cold water.

Also early last year before we turned off the heat it did work in that room but did not work in another room upstairs. Is it possible the air bubble has moved from 2nd floor to 1st floor over the summer while I did not run the heat.

Are there any ideas on what specifically I should do here to remove the air from the line and get my heat back.