I'm new to this forum but need some help. I have an oil fired furnance that heats the hot water in the winter and circulates the water through basebaord heaters. I had to modify the kitchen heater size when we re-modeled. I guess I have air in the system because the water doesn't circulate good anymore. How do I bleed the air out of this system (all copper pipe). I don't see any air bleed cocks in the system anywhere. Do I need to install some and if so, where at and does the bleed valve point up , down, or doesn't matter? Hope this makes sense.