My Rheem electric tankless water heater gives me the E5 error code when I turn one the shower in our master bathroom, but not in the other one. What might be causing
Firebird Boiler Error Codes & Troubleshooting
SOLVED: What does an E5 error code indicate? - Fixya
Error code 'E5' for type HC 23-84 by IBC Boilers. Cause and solution.