My rheem presege tankless hot water heater light is flashing

SOURCE: Rheem RTG 53 PVN with fault codes C4 or C7

I had the same problem with my tankless waterheater (flashing c4 76 alternately). I called Rheem
tech support and they had me 1 power down the remotepanel 2 unplug the unit from the wall 3 remove the cover 4 remove the wires for the remote panel from the circuit board and pull the twisted pair that goes to the remote out from the bottom of the unit. 5 reinstall the cover 6 plug the unit back
into the wall and turn on the hot water see if it works. It did in my case and they are sending me a new remote panel. I hope it helps.........

SOURCE: Paloma PTG 74PVN Tankless Water Heater

did you check the filters on the the water valves, i am not exactly sure about your codes that are shoeing but if you could read it and post them, i know on some of the units 76 means there is low water pressure and the filters are behind 2 caps one on each side above the shut off valve take off the caps and remove the screens, clean them and replace them ,, make sure you turn off the water on both side first or you will get wet

SOURCE: My Rheem Tankless Hot Water Heater is installed, but is it not attempting to start. The digital display keeps blinking 82, 0, 82 , 0 ...?

If this is a new board and Altidude chip with power on set dip switch 1 and 2 to on. Then press and hold adjust button until on board blinks fast then and you will see dashes on LCD display. Set dip switches 1 and 2 back to off. Turn on remote unit and you should see 100F. With any luck you are good to go.

SOURCE: rheem tankless water heater error code C4 13??

check diaphrapm valve or micro/switch best of luck

SOURCE: Rheem water heater turns off by its self

Flashing code 76 is lost communication between the remote and the burner control assembly CCA (circuit card assembly). The CCA is still under warranty if purchased within the last 3 yrs. Contact Rheem customer service and have your Mod. and S/N available....explain to the agent you are recieving - flashing code 76...they'll walk you through the process.