Convert original noise diagnostics call to maintenance tune up and cleaning. No unusual noises heard at this time during multiple on/off cycles from the thermostat and during test run. During initial walkthrough homeowners description of clunking noise was simulated by ducts popping when pushing on the return air drop. Shop-Vac all geothermal package equipment inside and out in the upper and lower blower and compressor compartments. Power flush and freshwater flush The drain pan, drain trap and drain lines to the common floor drain. Test run equipment in multi-stage cooling and confirm open loop water valve operation. Taco century valve is opening and closing correctly the way that it is installed however the valve body seals are worn out due to hard water and do seep water through during a closed or off position The 1/2-in PVC drain pipe exterior of the geothermal cabinet would function and be safe if rerouted or supported in a better fashion. Unfortunately half inch material is n