Yes. The thing is that I find these sounds to be soothing and part of a
house's personality. I wouldn't expect it in a brand new construction, but
over time, wood swells and sags. I like the noises my home makes!
However, when you completely drain a hydronic heating system, the new
water always has air dissolved in it. Usually the automatic air eliminators
do the trick, but sometimes it must be bled from the highest points in each
zone. Air doesn't make "clanking." It usually sounds more like water