I have a Rheem tankless pronto unit. I had a communications problem and changed the motherboard. I have a flashing 82 code. I've put the dip switch of 1 and 2 on, and pressed the adjustor button, but get the LH code. What should I do next?

Water Heaters - Rheem - Tankless Hot Water Heater Rtg-74pvp-2 7.4 Gpm