<strong>Yahoo Message Number: 98628</strong>I have been plagued for years with the heating system blowing cold air instead of warm. Was told it was a sticky check valve and I needed to tap the line to free it up. (not so easy at 4 in the morning) <br/> Turns out the problem was with the distribution pumps. They were a little corroded inside and would intermittently stick. I have the flapper...