hot water baseboard, cold upstairs after bleeding

ntextreme3

Split level house, the bottom floor is hot, upper floor is hot (not drawn in below), and the mid floor ("floor 2") is cold. In the [poor] drawing below, numbered circles are valves. Moved in this past Summer.

Had some trouble fully bleeding the system at first -- then noticed the boiler was set to over 240. I assumed the boiling water was creating air in the line. Turned it down to 180 and bled again.

When I bleed the system, water comes out from the second floor bleeders, but comes cold. I noticed that valve #4 felt hot before it, and cold after it. Line 3 (less than a foot away and off of the same line) is hot to where you can't touch it. It was also corroded and slightly leaking, so I thought I found my problem. Replaced the old valve, re-bled, and same. Seems to bleed fine (water comes out after air) but no heat.

Started to think it could be related to pressure, so I increased the pressure a bit (25-30 when cold) and tried again. I should mention here that there's a "third floor" (one room that is higher than all the other rooms) not pictured in the drawing because the lines come separately from the boiler and it didn't seem relevant to draw all of that. This "third floor" gets hot -- which deterred me from trying to increase the pressure - but not really seeing another way I gave it a shot.

Same result. Next I shut off valve 2 to the rest of the house, and it did seem to sound like more was flowing through the line that valve 3 and 4 come from -- but still no difference: The area around valve 4 remains cold. The last bleeder is all the way to the left of the pic upstairs right before it drops down -- so unless there's some kind of blockage within that drop I have no idea what else it could be.

Any suggestions on next steps ?

Alan Welch

How many zones? Does each level have it's own thermostat? Your problem may not be air, might be a faulty circulator, relay, zone valve or as simple as a thermostat needing batteries. Pictures of the boiler piping will help.