I have just moved into an old house in New Jersey and the house has two separate heating zones: one thermostat upstairs and one thermostat downstairs. The upstairs thermostat is currently inoperative, so a PSE&G technician circumvented the problem, and now both upstairs and downstairs are being regulated by the downstairs thermostat. The problem is there is no heat getting to the upstairs baseboard fin-heaters; the PSE&G tech said there is probably air in the line, and so bleeding is required. I tried to bleed the line as he had suggested but after I open the 30psi valve release, the hose I connected to the upstairs return-line drain faucet is NOT where the water comes out, but instead the water is being discharged out the 'emergency' valve which has no threaded line for a hose connection; and anyway I think the water is not being 'pushed' upstairs and back down the upstairs drain, but just to the emergency valve. Could someone help me, we're freezing upstairs?

I believe from what you have posted this system could be a problem. Before things get out of hand I suggest you call a professional for ON SITE service. The water should not be coming out of the emergency POP OFF valve. You have way too much pressure going to the system. Call for a on site inspection and repair.

It seems to me as if u have what u call zone valves. 2 small square boxes on the riser pipes to your boiler.
At the bottom of th silver the boxes there a little piece of metal sticking out.
The metal is attached to a spring loaded valve. Pull the metal back and hook it to a noch. U will hear the water flowing as soon u pull the clip back.
If so then that is the problem. Run the system and have a tech rewire your zone valves to the thermostat.