Rheem Proterra Hybrid water heater was displaying error code A108 for a blockage in the condensate line. Disassembled condensate outlet. Inspected inside of the unit in the condensate tray and found some sludge built up. I cleared the debris out of the unit and reassembled the drain line. I added a tee with a short stand pipe to the drain. Tested thermistors for faults. All readings were within manufacturer specifications. Thank you for choosing TE Certified!