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The four most popular error codes and how to resolve them

FOUNTAIN VALLEY, CALIFORNIA — For more than 60 years, Noritz has built an international reputation as a leading innovator, manufacturing reliable, energy-efficient tankless water heating products with superior quality. Still, error codes are inevitable due to a variety of external and internal factors.

In this article, Noritz Application Engineering and Service Training Supervisor Eric Manzano identifies the most common error codes and their causes, while also providing effective solutions to prevent system malfunction.

Error Code 11

Three elements are needed to ignite a tankless water heater: air, spark, and gas. When a tankless water heater ignites, the fan within the heater will also activate. Through the unit’s sight glass window, you should be able to see the ignition spark a flame.

Error Code 11 indicates that one or more of these elements are not present.

Different factors could cause a malfunction, such as no propane in the storage tank, disruption in gas-supply line, problems with airflow, or debris on the ignition plug. Any of these can cause Error Code 11 to appear.

Solution: Verify the unit and the gas supply match, whether natural gas or propane, and verify the value of the gas pressure with a digital gas manometer. This common tool provides a value reading to indicate gas pressure issues accurately.

If a flame is not visible, check the voltage supply to the ignition plug with a multimeter. You have the option to remove the igniter and physically activate it to see if sparks occur.

Error Code 12

Similar to Error Code 11, Error Code 12 indicates a flame-loss problem. The flame has been ignited, but does not stay lit, causing insufficient heat to bring the water to the desired hot water temperature.

With propane installations, the low storage-tank volume will cause flame loss. The heater will work to adjust to the gas pressure in the unit at some sacrifice to overall volume and pressure performance.

But when multiple heating appliances are used simultaneously, such as during the winter months, an undersized gas supply will prevent the water heater from reaching  its maximum performance level. Poor gas pressure supply weakens the flame, so that it cannot meet higher demands of hot water usage

Tankless water heaters favor temperature over volume. The result with this error code? Your water will reach the desired water temperature, but severely decrease the water volume and  pressure to all the hot-water outlets in your home.

Solution: Use a digital gas manometer to obtain an accurate reading of the gas pressure. Call Noritz customer care or technical support to help diagnose and repair this issue.

Error Code 90

Tankless water heaters will make three attempts to reach the desired water temperature. After a third failed attempt, the heater will display Error Code 90, which derives from one of two conditions.

Similar to Error Codes 11 and 12, insufficient external gas pressure will trigger Error Code 90. The second scenario is an internal issue requiring maintenance. The combustion air route of the air intake and exhaust must be inspected, as well as the general cleanliness of the unit.

Solution: Once again, a digital gas manometer will accurately identify the gas pressure within the unit. If the problem is internal, an air compressor is used to clean the unit of dirt and built-up lint debris, cleaning the unit’s interior and improving the air quality.

Flow Malfunction

If a hot-water fixture is turned on, but does not trigger the tankless unit to send hot water, the unit may not display an error code.

Why no error code in this situation? Noritz tankless units will meet a hot-water demand as small as 0.5 gallons per minute, the minimum. But hot-water demand is what activates a tankless water heater — including the display of error codes. If the heater does not detect any flow demand, no error code can be displayed.

Solution: There are diagnostic channels to the tankless water heater to monitor flow rate and temperature output remotely. Contact Noritz directly to walk you through keypad navigation to determine the current flow rate and temperature output, and to establish whether the demand from that hot-water fixture is sufficient to turn on the water heater.

Noritz customer service or technical support can help remedy all three error codes, as well as flow-malfunction issues. Noritz customer service and technical support are available Monday through Friday from 5:00 am to 6:00 pm Pacific; Saturday through Sunday from 10:00 am to 3:00 pm PST. Call 1-866-766-7489 (1-866-7-NORITZ).

If you are interested in technical training, Noritz University offers self-paced courses or webinars. Contracting companies interested in additional training can do so online or in person at the Noritz Headquarters facility in Fountain Valley, California.