Noritz Error Code 43: Water Level/Neutralizer Issue

How to Fix Noritz Code 43

1. Check if the water level is low. If it is, top it off using the fill valve.
2. If the water level is normal, don't attempt to fix the neutralizer or sensor yourself. Call a professional.
3. When calling a pro, have the model number ready for a faster diagnosis.

How to Reset Noritz Code 43

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 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.

Common Causes

• Low water level in the heater
• Faulty water level sensor
• Neutralizer not functioning properly
• Incorrect water chemistry

Diagnostic Steps

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Noritz model families as 43.