In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
grundfoss flowcheck chatter
when a flow check valve chatters, it's because of
air in the system, but it doesn't seem like you have
a problem with air, i believe your problem is in the flow
check valve. without air in the system a bad flow valve could still make chatter sounds useually when the circ is on. i have replaced many flow valves for that reason. plus on a too much heat call the weight in the flow check is useually hung up.