We have an approx 8 y/old Grundfos recirc pump on our hot water line and today I notice it is making a ticking noise (first time I've noticed this) and it is "quite" warm to the touch--I've never touched it before so I'm not sure if this is always the case. Should I be worried? I don't recall that it made a ticking sound previously and I'm about to go out of town overnight... any help is apreciated.