gun to my head

blackpipe

steam comes up the pipe and stops below the floor on the third floor ,so the radiators on the third do not get hot the pipes in the floor are steaming hot but the pipe leading up from the third to the fourth including the radiators are cold

jpf321

need more info

pressure setting?

EDR load?

boiler make and specific model?

boiler rating in BTU or sq ft of steam if stamped?

1-pipe 2-pipe?

TRVs installed?

type of rads? baseboard, free standing, convectors?

did it ever work?

type of vents if any on rads?

is the system balanced?

also see this radiator checklist here: http://www.heatinghelp.com/forum-thread/129206/Radiator-not-getting-any-heat#p1185051