Customer ordered replacement cartridge for shower in hall bath in main floor with cross connection. Replaced the cartridge. Tested the cross connection and found a secondary cross connection was allowing some crossover still. Customer stated that since it’s a less severe cross connection that he will wait on further diagnosis to see how the house temperature is affected. Customer removed penal for hall tub to see if s mixing valve was present. There was no mixing valve for the tub that could be allowing a cross connection. Showed customer where the limiter button in the trim had dry rotted and was no longer functioning. Also pointed out that the shower head had low flow and likely needed to be addressed with replacement. Customer had questions regarding filtration for the home. Left quote for new reverse osmosis system and kitchen faucet. Replaced cracked slip joint under sink as a courtesy.