What 71 means
A fault with the gas solenoid valve.
Likely causes
- Solenoid valve or wiring fault
Safe first checks
- Note the code.
When to stop
Gas valve work is only for a qualified gas technician.
Checked against: Rinnai: Troubleshooting Tankless Water Heater Diagnostic Codes (100000652). Codes can differ by model and year, so confirm with your owner's manual.