Poly-B products are under a class action suit due to splitting ect. Manufacturers names of the poly-B products escape me. Dow chemical might be one but I am not sure. You should hire a plumber to identify your water lines if they are plastic in nature. Ipex or Pex products are the best on the market for domestic water lines and floor heat ect.
If you are in a condominium under warranty from the builder it is critical to hire a independant plumber that has nothing to do with the original construction project. The last thing the plumbing contractor will do is admit wrong doing. It will cost him money and lots of it.
There are poly-B to Pex adapters to get around the problem the best you can.