Customer called about a leak near their garbage disposal. Arrived on site and inspected disposal. Ran water, water leaking through all openings on the bottom of the disposal. Also, customer was having issues with temperature fluctuations at their master shower and wanted a customer supplied shower head installed. Provided pricing to replace the disposal and perform a diagnostic on the fluctuating water temperature. Customer accepted. Removed previous disposal and under sink waste pipe. Installed new 1/2 hp disposal and under sink waste pipe. Performed 6 drain down tests, no leaks detected, draining as intended. Operated disposal, working as intended. Home has a comfort series pump and manifold installed in the same bathroom as the shower. Isolated manifold, problem remained. No other fixtures in the home had temperature problems. Waived diagnostic and charged for a cartridge replacement. Shut off water, removed trim and cartridge. Inspected inside of valve, small signs of corrosion. In