Homeowner has been having issues with intermittent hot water in some of the fixtures throughout the house. Upon inspection the swing check valve was showing signs of dezincification. Along with the fact that there was no check valve on the recirculating line. I disassembled and installed the new spring check on cold water and the recirculation line. Added a shutoff valve on the inlet cold and recirculating line. Mounted the pump to a 2x4 for proper support. Moved the expansion tank to after the check valve to protect the system. Pressurized water and verified proper operation.