Rinnai Error Code E4
Fault: Indoor heat exchanger outlet temperature sensor (T2B) error
Applies to: Rinnai Outdoor Units – DONSR20Z9, DONSR24Z9Units and Indoor Units – DINLR20Z7 , DINLR24Z7
Error codes identify when something may need to be repaired or isn’t functioning properly. Each error code has a meaning to help you understand the problem and what needs to be done to fix it.