Noritz Error Code 90: Combustion Abnormality
Warning: Your Noritz water heater has detected a combustion issue. It's safe to use, but needs professional attention.
How to Fix Noritz Code 90
- Check your gas supply valve to ensure it's fully open
- Listen for the ignition system to spark when you turn on the heater
- If the problem persists, contact a professional HVAC technician
How to Reset Noritz Code 90
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does 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.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Ignition System | NOR-IGN-01 | — |
| Burner Assembly | NOR-BURN-01 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 10 | Flame Failure | Warning |
| 11 | Ignition Failure | Warning |
| 12 | Flame Loss | Warning |
| 14 | Thermal Fuse Failure | Warning |
| 16 | Over-Temperature | Warning |
| 29 | Condensate Drain Issue | Warning |
| 31 | Inlet Thermistor Failure | Warning |
| 32 | Outlet Thermistor Failure | Warning |
| 33 | Heat Exchanger Thermistor Failure | Warning |
| 43 | Water Level/Neutralizer Issue | Warning |