Arrive and found there was no power to the unit. Reworked and restored power to unit to allow it to properly heat water in the home. Isolated the outgoing hot line and waited 10 minutes to confirm water is heating up. Customer stated that there was hot water upstairs but none in basement or main floor. Since there was no power to the new unit in the basement since yesterday there should have been no hot water anywhere. Found an almost 15 year old tankless unit in the attic with no service history and a code for heavy scale flashing. This unit needs to be replaced as any servicing of an unserviced tankless after around 7 years is too likely to cause leaks. Will return tomorrow to install tankless unit and restore proper hot water to the house.
