Noritz Error Code 43: Water Level/Neutralizer Issue
Warning: Your Noritz water heater has detected a water level or neutralizer issue. It's safe to use, but needs professional attention.
How to Fix Noritz Code 43
- Check if the water level is low. If it is, top it off using the fill valve.
- If the water level is normal, don't attempt to fix the neutralizer or sensor yourself. Call a professional.
- When calling a pro, have the model number ready for a faster diagnosis.
How to Reset Noritz Code 43
- 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 43 mean?
Error code 43 on your Noritz water heater indicates a problem with the water level or neutralizer. The neutralizer is a component that maintains the water's pH balance, preventing corrosion. If this system isn't working correctly, it could lead to premature equipment failure. The water level sensor ensures your heater has enough water to operate safely and efficiently.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Water Level Sensor | NOR-100012 | — |
| Neutralizer | NOR-100015 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 10 | Flame Failure | Warning |
| 11 | Ignition Failure | Warning |
| 14 | Thermal Fuse Failure | Warning |
| 29 | Condensate Drain Issue | Warning |
| 31 | Inlet Thermistor Failure | Warning |
| 32 | Outlet Thermistor Failure | Warning |
| 33 | Heat Exchanger Thermistor Failure | Warning |
| 45 | Water Leak Detected | Warning |
| 51 | Fan Motor Failure | Warning |
| 61 | Fan Motor Failure | Warning |