Arrived on site removed board on unit and discovered that the heat exchanger is leaking. Contacted Navi and tech-support and got the heat exchanger covered under warranty. Gave options to customer about installing a new tankless versus replacing the heat exchanger PCB board and flow sensor. Customer would like to move forward with installing new tankless, we are going to email the save green form to them to fill out and we are going to perform the work tomorrow morning told customer that if they do not qualify for save green, then they will need to pay the amount in full or they can do financing through my guy plumbing. Applied tech-support fee towards cost of replacement of the unit.