Banging pipes making me crazy! We had a renovation done several years ago and ever since the base board hot water pipes have been banging. I have confirmed with our gas company and HVAC contractors that It is not AIR in the system . We even had it drained. The boiler is about 8 years old and has several air release mechanisms to prevent air getting trapped in the system. So I assume that the pipes were not properly secured when the renovation was complete. How do I pinpoint where to begin looking for the source without tearing open a bunch of walls / ceilings?