Rinnai Tankless Water Heater Error Code 58: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
Error Code
58
Brand
Rinnai
Product Type
water_heater
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code 58 on your Rinnai tankless water heater indicates a short circuit in solenoid valve 4. This valve controls gas flow to the burner, and a short can prevent the unit from firing. The fix involves checking wiring and possibly replacing the solenoid assembly.
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Tools You'll Need

How to Fix Error Code 58

  1. Turn Off Power and Gas

    Never work on electrical components while power is connected. Gas leaks are hazardous; if you smell gas, evacuate and call a professional.
  2. Access the Solenoid Valve Assembly

  3. Inspect Wiring for Solenoid 4

    Use proper electrical safety: ensure power is off before touching wires.
  4. Test Solenoid Valve 4 Resistance

  5. Replace Solenoid Valve Assembly if Faulty

    Always use manufacturer-approved replacement parts to ensure safety and warranty compliance.
  6. Reassemble and Test

Parts You May Need

Rinnai Gas Solenoid Valve Assembly
Check Price on Amazon
Rinnai Gas Solenoid Valve Assembly
Check Price on Amazon
Rinnai Gas Solenoid Valve Assembly
Check Price on Amazon
Rinnai Gas Solenoid Valve Assembly
Check Price on Amazon
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When to Call a Professional

If the wiring and solenoid check out fine but error 58 persists, the control board may be damaged. For any gas line work or if you're uncomfortable with electrical troubleshooting, call a licensed HVAC technician or Rinnai service provider.

Frequently Asked Questions

What does error code 58 mean on a Rinnai water heater?
Error code 58 means there is a short circuit in solenoid valve 4, which controls gas flow. This prevents the heater from lighting.
Can I fix Rinnai error 58 myself?
If you are comfortable with electrical testing and simple part replacement, yes. Otherwise, hire a professional.
How much does it cost to replace a Rinnai solenoid valve?
The part costs around $50-$150, plus labor if you hire a technician. DIY saves on labor costs.
Will error 58 clear after replacing the solenoid?
Yes, replacing the faulty solenoid typically clears the error. If it doesn't, the control board may be damaged.
How do I find solenoid valve 4 on my Rinnai heater?
Solenoid valves are arranged in order on the gas manifold. Solenoid 4 is usually the fourth from one end. Check your unit's wiring diagram for exact location.