For this job, the customer was having issues with the hit water, after further diagnosis we removed the insulation from the recirculation line. Once we removed insulation there was no check valve installed on the return causing crossover. To fix issue we installed a new check valve on the return, and replaced the check valve on the cold inlet as well. Once complete we installed a boiler drain on the return bled out the air from the return line, and tested our work. Every fixture in the home got hot. We set the temp to 120 degrees on heater.