Hot Water Boiler not getting hot
	
	
		Hello. I have a Utica Boiler, hot water system. It's pretty old but has run well before. I had a new expansion tank installed last season, no problems at all.
This year, with the cold weather in Northeast, my radiators are not getting hot. The feed line coming from the boiler is barely warm, the return lines are cold. The thermometer reads 80 degrees, but is set at 200 (I just raised the temp to see if that would help, but it didn't). The pressure is at a steady 20#.
I did not bleed out the radiators this year. Is that something I should do before calling in someone? They were bled out when the tank was put on last year, so I wasn't sure if I needed to do it again.
Thanks for your suggestions.