Noritz tankless water heater error codes

Noritz tankless water heaters provide an instant supply of hot water and prove their worth by being efficient. Additionally, they are able to speak to each other using error messages. The alpha-numeric and numeric messages are displayed on either an LED on the appliance or a remote control. Each entry links to a particular situation inside the appliance so that a homeowner or a serviceman can address a problem before a small problem turns into a large one. Disregard for these messages results in a reduction in performance and increased costs to fix.

What are error codes on a Noritz tankless water heater?

You see an error code when the heater detects something unusual. These Noritz tankless water heater error codes serve as shorthand for specific operational problems. All of these codes, whether numerical or alpha-numeric, are associated with a system or fault, like ignition, flame detection, water flow, temperature, and/or internal communications. Certain codes show a transient problem while others show a system no longer functioning.

The use of the codes, however, can be seen clearly in their role. They indicate where the first place should be looked at. Of course, it does not necessarily follow that every home owner will do the repair work. The code does remove much of the guesswork and speeds the diagnosis of Noritz system errors. Randy Oshiro at Noritz has noted how these messages catch developing faults that might otherwise remain invisible until the unit quits. Spotting an early problem often saves money and time.

Treat codes as active clues. Acting promptly preserves efficiency and helps keep hot water available.

Common Noritz tankless water heater error codes

Some codes appear more often because they relate to the core elements of combustion and water heating. While the complete Noritz error codes list covers various technical scenarios, certain issues occur more frequently. 

Ignition/Combustion Errors: These are mostly caused by gas delivery problems, air flow, or air-gas proportioning. Issues related to temperature errors are typically generated by insufficient water flow or-scale buildup or bad sensors. In condensing units, condensation problems are generated if drain lines become fouled, frozen, or pitched improperly. Communication Errors: These situations mostly occur due to power conditions, improper adjustment, or problems within the control boards.

These conditions trigger safety shutdowns because they interfere with stable operation or safe combustion, making these codes the most frequently reported during diagnostics.

Why do Noritz error codes appear?

Most codes come from a handful of familiar categories identified during Noritz heater troubleshooting. Gas supply problems, specifically gas pressure issues, show up as ignition and combustion errors. Issues with water flow cause temperature and overheat faults. Also, electrical and sensor failures provide a host of sensor and communication codes. Combustion and venting problems manifest as combustion issues. Mineral scale, condensate drains, and neutralizer exhaustion are maintenance-related issues that generate periodic faults. Multiunit installations and remote control wiring add another layer where wiring or signal issues can produce communication faults.

Can you reset a Noritz tankless water heater?

A reset often clears transient electronic faults and lets the unit attempt a normal startup again. While many tankless water heater error codes on Noritz units are temporary, a reset will not fix a failed sensor or a mechanical defect. If the code returns immediately the underlying fault remains and further diagnosis is required.

Use this basic reset procedure:

1. Turn off the power. Locate the circuit breaker dedicated to the tankless water heater and switch it to the Off position.
2. Wait. Leave the unit without power for at least 30 seconds and ideally a full minute.
3. Restore power. Switch the circuit breaker back to the On position.
4. Observe. Watch the display to see whether the code clears and whether the unit attempts to ignite and heat water.

Certain models include a reset button on the control panel or remote. Holding that button for a few seconds can achieve the same result. When an error reappears shortly after a reset, a simple power cycle will not fix the problem; in such cases, professional diagnosis or routine maintenance is needed to ensure long-term reliability.

When to call a professional for Noritz error codes

Some issues can be handled with basic checks. However, accurately interpreting Noritz water heater error code meanings is crucial, as others require a licensed technician when safety is at stake. Gas, combustion, and venting faults can be hazardous if mishandled. If you feel uncertain, stop and call a pro.

Call a professional in these situations: persistent error codes which keep popping up immediately after a reset, Gas or Combustion errors indicated by codes 11, 12, or 90, Visible leakages or unusual noises related to mechanical portions like the heat exchanger, fan motor, gas valve, or circuit board in your tankless hot waters unit, No hot water situation after conducting initial tests to check whether the issue is something that can easily be resolved.

If you prefer, American Choice Plumbing provides a professional plumbing service to inspect the unit, interpret the code, perform safe gas checks, and recommend repairs or parts replacement. A careful diagnosis prevents unnecessary part swaps, preserves the water heater lifespan, and keeps the system operating with optimal energy efficiency.