Noritz Error Codes:

Just like all equipment, it must be maintained in order for it to run optimally. A regular scheduled maintenace is best for a high efficiency combi-boiler. If your Noritz unit displays an error code, contact Green Heating and Air for a fix. Example of most common error codes are:

• Error Code 11: The unit recognizes a call for hot water but fails to ignite the burner. It could be due to insufficient gas supply or pressure, blocked airflow (intake or exhaust vents), debris, faulty ignition plug/rods, issues with the flame sensor, or potentially a problem with the gas valve.
• Error Code 12: The unit successfully ignites, but the flame either goes out during operation or is too weak to heat the water properly. Potentially it could be insufficient gas supply or pressure, airflow problems, clogged or dirty burner components, or issues with the gas valve.
• Error Code 16: When the outlet water temperature spikes significantly higher than the set point. The most frequent cause is mineral scale buildup on the heat exchanger, especially in areas with hard water. This buildup reduces heat transfer efficiency, forcing the unit to run hotter to compensate. Low water flow through the unit can also contribute. Regular descaling is the primary fix and preventative measure.
• Error Code 90 / 99 / F90: Improper mixture of air and fuel for combustion. The unit may attempt ignition several times before displaying this code lockages in the air intake, exhaust vent, or debris in the fan motor. Insufficient gas supply or pressure
• Error Code 16: It can be due to scale buildup in the heat exchanger, reducing efficiency, restricting water flow, and potentially causing overheating and component failure over time.
• Error Code 29: The unit is unable to drain the acidic condensation produced during operation. This is specific to condensing boiler models.
• Error Code 31, 32, 33: Themistor issues.
• Error Code 61: Fan motor failure.
• Error Code 73: Circuit board setting errors.