[kapchis]

We are in a new-to-us house that we did a complete renovation on, mostly due to the bursting of the polybutylene pipes 10 days after closing. We had the entire house repiped with copper. The job went well and the pipes work fine..... but
there is a "CLANK" noise, mostly at night, that happens at about 10 minute intervals. There are three spots in the house where we notice it. Two more often that the third. It doesn't matter if anything running, it still happens. I do tend to notice that it happens more often if something is running. I've been considering calling the plumber/installer back, but I'm pretty much figuring I'll get the run around about what it is.
Any ideas out there? Anything we should look at?