How sick of me are you guys? :-)

The same thing happened with the hea two days in a row - tell me what
you think...

I get home, turn up the thermo from 62 to 72, system kicks on - I wait
10 minutes, then I bleed all the radiators again - from top to bottom
(all give out only clear water), then I go to check on the boiler.
outbound pipe that has the issues was hot, then it went cold (while the
burner is cooking!)...all the inbound pipes were hot.

I check the radiators, only 5 of the 8 are hot. Two are cold, one
lukewarm. I mean ice cold...I do a quick bleed on these two, and cold
water comes out...

Back to the basement - the system kicks off - the air release valve
over the expansion tank gives off 4 or 5 quick hisses, then the
circulator on the inbound pipe kicks in, then the burner turns back
on...at this point, the outbound pipe gets hot -real hot, and in 5
minutes the three cold radiators are blazing hot.

So essentially, If I waited 20 minutes, all the radiators would get
hot, just some faster than others...Is this right?

Also, my expantion tank has a air nipple on the bottom, like on the
tire of a bike...Is this to pump in air or to let it out?
Thanks,


Bluesman