71 Moderate Hard — consider a tech

Rinnai Tankless Water Heater 71 — Gas Solenoid Drive Circuit Fault

Rinnai Tankless Water Heater · Error code 71

What 71 Means

The PCB has detected an abnormal condition in the solenoid drive circuit.

Symptoms

  • Code 71 on power up or ignition
  • No burner operation

Common Causes

1
PCB drive circuit failure

Board can't actuate solenoid correctly.

2
Shorted solenoid coil

Pulling abnormal current.

3
Wiring short

Harness shorted to chassis.

How to Fix It

  1. Power down and inspect gas valve wiring for damage or shorts to chassis.
  2. Measure solenoid coil resistance — replace gas valve if out of spec.
  3. If wiring and valve are good, replace the PCB.

More Rinnai Tankless Water Heater Codes

02 02 — Power Interruption / Memory Loss 03 03 — Loss of Communication / EZConnect Issue 10 10 — Air Supply or Exhaust Blockage 11 11 — No Ignition 12 12 — Flame Failure 14 14 — Thermal Fuse / Overheat Cutoff

All Rinnai codes → All tankless water heater codes →

Verified against manufacturer documentation: rinnai.us

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.