Put new ciculating pump on furnace.. bled entire system,but can't seem to keep my pressure at 20#.. what it calls for.. wake up and its almost at 30#.. drain it down to 20# and then it drops even lower?. going crazy.. any help would be great

I don't know much about that, but I do know who you could ask. You need to ask the place where you got the furnace piece from, and if they don't know,then just ask them if you could try something better