Noritz Error Code 90: Combustion Abnormality

How to Fix Noritz Code 90

1. Check your gas supply valve to ensure it's fully open
2. Listen for the ignition system to spark when you turn on the heater
3. If the problem persists, contact a professional HVAC technician

How to Reset Noritz Code 90

1. Turn off the unit using the power button on the front panel.
2. Turn off the gas supply valve.
3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
4. Restore power at the breaker, then open the gas valve.
5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Noritz Error Code 90 Mean?

Error code 90 on your Noritz water heater indicates a combustion abnormality. This could be due to improper gas supply, a faulty ignition system, or a problem with the burner itself. The unit has safely shut down to prevent further issues. While it's still safe to use, it's important to have a professional diagnose and fix the problem to ensure your water heater is working efficiently and safely.

Common Causes

• Insufficient gas supply
• Faulty ignition system
• Burner problems

Diagnostic Steps

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Noritz model families as 90.