Rinnai 71
Rinnai code 71: gas solenoid valve fault
Short answer
Code 71 is a fault in the gas solenoid valve circuit, the electrically operated valves that open and close the gas supply to the burner. Technicians check the wiring, measure solenoid resistance and voltage, look for moisture in the gas valve area, and replace the gas valve or control board.
In this guide
Gas reaches a Rinnai burner through solenoid valves, which the control board opens and closes electrically. Code 71 means the board has detected a problem in that circuit.
Rinnai makes several generations of tankless heaters (SENSEI, SENSEI RX/CX and older non-SENSEI models). The meaning below comes from Rinnai's own diagnostic code guide; the exact service steps differ slightly between generations.
If you smell gas, do not reset the unit or touch any switches. Leave the building and call your gas utility from outside.
Common causes
- Wiring problems between the solenoids and the control board
- A solenoid coil that has failed open, found by measuring its resistance
- Moisture. On older models Rinnai tells technicians to check the plastic tubing from the combustion box to the gas valve for water. Moisture there can come from a leaking heat exchanger or from condensation running back down the vent.
- A mechanical problem inside the valve, even when the resistance readings look normal
- A setting on the control board. On newer models Rinnai notes a DIP switch that shuts off the main gas valve for testing must be in the OFF position.
Why moisture matters
If water is found in the gas valve area, the valve is replaced and the source is tracked down. A leaking heat exchanger has to be replaced; condensation from the vent is handled by adding a condensate drain to the vent system. Fixing only the valve would bring code 71 back.
What homeowners can do
Reset the unit once from the controller. If code 71 returns, turn the heater off and call a licensed installer. Mention any water you have seen dripping from the unit or the vent.
See the full list on our Rinnai error codes page.
Common questions
Is Rinnai code 71 a gas leak?
No. It is an electrical fault in the gas valve circuit. If you do smell gas, leave the building and call your gas utility from outside.
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Other Rinnai codes
| Code | Meaning |
|---|---|
| 02 | No burner operation during freeze protection |
| 03 | Power interruption during bath fill |
| 05 | Bypass flow control device fault |
| 10 | Air supply, exhaust blockage or condensate trap full |
| 11 | No ignition |
| 12 | Flame failure |
| 14 | Thermal fuse or overheat sensor tripped |
| 15 | Venturi control fault |
| 16 | Outgoing water temperature too high (safety shutdown) |
| 17 | Venturi blockage |
| 19 | Electrical grounding fault |
| 21 | Data transfer error after a control board replacement |
| 25 | Condensate drain clogged or condensate pump error |
| 32 | Outgoing water temperature sensor (thermistor) fault |
| 33 | Heat exchanger temperature sensor (thermistor) fault |
| 34 | Combustion air temperature sensor fault |
| 38 | Exhaust gas temperature sensor fault |
| 41 | Freeze protection sensor fault |
| 51 | Inlet water temperature sensor fault |
| 52 | Gas valve or modulating solenoid valve signal fault |
| 54 | High exhaust gas temperature |
| 57 | Burner overheat switch open |
| 58 | Secondary heat exchanger overheat |
| 61 | Combustion fan motor fault |
| 63 | Recirculation low flow |
| 65 | Water flow control device (servo) fault |
| 70 | Control board (PC board) fault |
| 71 | Gas solenoid valve circuit fault |
| 72 | Flame rod (flame sensing) fault |
| 73 | Burner thermocouple fault |
| 79 | Water leak detected inside the unit |
| LC | Scale buildup in the heat exchanger |
| SS | Service soon (maintenance reminder) |
| FF | Maintenance has been performed (service history marker) |