i have had a greenwood boile for 4years , it had some issues to work out ,but i had it running good . this season i fired it up and noticed i could hear the fliud running in the lines ,furthur more the damper motor wanted to open and close at will and below operating temp .I thought the pump was maybe cavitating and replaced the cartriage and it still makes water flowing noise also the damper motor is now closed and will not open . I could use some advice