I have a small problem I need help with. I have forced hot water with baseboard heat. My expansion
tank sprung a leak last week. I replaced it by spinning the old one off and spinning the new one
on. In the process I lost some water. My problem is that now when the heat comes on I hear water
running through the baseboards. I know there's a way to bleed the zones but I have forgoten how. I
also remember it has something to do with the faucet and shut off valves at the end of each zones
run back to the furnace. One last thing, on the top of the manifold that the expansion tank
attaches to, there's a small round part with what looks like a tire valve stem on the top of it. It
has a cap on the stem and when I loosen the cap, water starts dripping out. Is this some kind of
bleeder ??? Do I leave the cap loose and let it drip ????

Thanks
Brian