Upon entry into the home, customer stated that he does not have good water pressure on the hot side going into his master bathroom. Customer also stated that the hot water runs out drastically when using the dishwasher and or washing machine and trying to take a shower at the same time. during my initial investigation, I came to the conclusion that the 15 year-old exterior tankless heater is not working sufficiently for proper flow rate and needs to be changed out. I provided an estimate to change out this exterior heater. At this time, both of customers drains were draining properly, so no sneaking services needed.