Hardness 4 ph 7 pressure 60 Arrived on site customer stated that they would like their navien tankless flushed. After inspecting we found that the unit is 9 years old and has never been serviced. Myguy plumbing explained to the customer that since the unit is 9 years old and has never been flushed, if we flush it, we can be asking for issues with the unit. Customer has hot water and everything is functioning as should. Myguy plumbing would not recommend to flush the unit. For today we collected the visual diagnostic.