Noritz Error Code List PDF: A Comprehensive Guide
Navigating Noritz tankless water heater issues requires understanding error codes; a detailed PDF guide empowers homeowners to troubleshoot or call for expert assistance promptly.
Understanding Noritz Tankless Water Heaters
Noritz tankless water heaters represent a significant advancement in home comfort, offering on-demand hot water and eliminating the energy waste associated with traditional tank systems. These units, however, utilize complex technology, relying on a network of sensors and components to ensure safe and efficient operation. When issues arise, the system communicates through error codes – digital signals indicating a specific problem within the unit.
Understanding these codes isn’t about becoming a certified technician, but rather about gaining enough knowledge to assess the situation. Knowing if an error suggests a simple reset or a potentially serious issue can save time and prevent further damage. A comprehensive PDF guide detailing these codes is therefore an invaluable resource for any Noritz owner, bridging the gap between homeowner and professional service.

Why Error Codes Appear
Noritz tankless water heaters employ sophisticated monitoring systems to maintain optimal performance and safety. Error codes aren’t malfunctions themselves, but rather symptoms of an underlying issue detected by these systems. These codes appear when sensors identify deviations from normal operating parameters – things like incorrect water temperature, insufficient gas supply, or problems with the ignition process.
The system’s self-diagnostic capabilities are crucial. They prevent potentially dangerous situations by shutting down operation when a problem is detected. Ignoring an error code can lead to reduced efficiency, component damage, or even safety hazards. A detailed PDF error code list provides the key to deciphering these signals, allowing homeowners to understand the nature of the problem and determine the appropriate course of action.
Locating the Error Code
Finding the error code on your Noritz tankless water heater is the first step towards diagnosis. Typically, the error code is displayed on the unit’s control panel – a digital screen located on the front or side of the heater; The exact location can vary depending on the model, so consulting your owner’s manual is recommended.
Some models may require a specific button press to activate the display. The PDF error code list often includes diagrams illustrating where to find the display on different models. Once visible, carefully note the two-digit (or sometimes three-digit) code. This code is your key to understanding the problem. Referencing the official Noritz documentation, or a comprehensive PDF guide, will unlock the meaning behind the code.
Common Noritz Error Codes ⎼ General Categories
Noritz error codes, detailed in the official PDF documentation, generally fall into several broad categories. These include issues related to basic operation, such as flame rectification or water flow problems. Gas supply and combustion errors are also frequent, indicating potential issues with the gas valve or ignition system.

Sensor and component failures represent another significant category, pointing to malfunctioning temperature sensors or other vital parts. Finally, advanced system errors can signal communication problems between units or activation of freeze protection. A comprehensive PDF guide categorizes these codes, allowing for quicker troubleshooting. Understanding these general areas helps narrow down the potential cause before diving into specific code definitions.

Error Code Range 1-10: Basic Operational Issues

Noritz tankless water heater error codes 1 through 10, as outlined in the official PDF manual, typically indicate fundamental operational problems. These are often the easiest to address, frequently involving simple resets or checks. Common issues within this range include problems with flame rectification – ensuring the burner is lit correctly – and overheat errors, signaling a potential safety concern.

Water flow errors are also prevalent, suggesting insufficient water pressure or a blockage. The PDF guide details each code, providing initial troubleshooting steps. Addressing these basic issues promptly can prevent escalation to more complex problems, saving on potential repair costs and ensuring consistent hot water supply.
Error Code 1: Flame Rectification Error
Error Code 1 on a Noritz tankless water heater, detailed within the official PDF documentation, signifies a “Flame Rectification Error.” This means the unit detects the gas is flowing, but isn’t sensing a stable flame. The PDF guide suggests checking the gas supply first, ensuring it’s fully open. A dirty or faulty flame sensor is a common culprit, requiring cleaning or replacement.
Insufficient gas pressure can also trigger this code. It’s crucial not to attempt repairs involving gas lines yourself; always consult a qualified technician. The PDF emphasizes safety, warning against repeated ignition attempts. A persistent Code 1 indicates a potentially dangerous situation requiring professional diagnosis and repair to restore safe operation.
Error Code 3: Overheat Error
Noritz tankless water heater Error Code 3, thoroughly explained in the official PDF manual, indicates an “Overheat Error.” This critical fault signifies the unit’s internal temperature has exceeded safe operating limits; The PDF stresses immediate shutdown to prevent damage or potential hazards. Common causes include restricted water flow – check for partially closed valves or sediment buildup.
A malfunctioning high-limit switch or a failing circulation pump can also trigger this code. The PDF advises against repeated resets, as this won’t resolve the underlying issue. Professional inspection is vital to identify and rectify the cause, ensuring the unit’s longevity and safe operation. Ignoring this error can lead to component failure and costly repairs.
Error Code 4: Water Flow Error
Noritz tankless water heater Error Code 4, detailed in the comprehensive PDF guide, signals a “Water Flow Error.” This indicates the unit isn’t detecting sufficient water flow to initiate or maintain operation. The PDF highlights several potential causes, starting with checking for closed or partially closed inlet water valves. Sediment buildup within the heat exchanger is another frequent culprit, restricting water passage.
Low water pressure, a failing flow sensor, or even air trapped within the lines can also trigger this error. The PDF recommends flushing the system to remove debris. Repeated occurrences necessitate professional diagnosis to pinpoint the root cause and prevent further damage. Ignoring this code can lead to overheating and component failure, requiring expensive repairs.
Error Code Range 11-20: Gas Supply & Combustion Problems
The Noritz error code PDF designates codes 11-20 to issues concerning gas supply and the combustion process – critical areas for safe operation. These errors often indicate potentially dangerous situations requiring immediate attention. Common problems include insufficient gas pressure, a malfunctioning gas valve, or issues with the ignition system. The PDF stresses the importance of never attempting self-repair with gas appliances.

Codes within this range frequently point to blocked venting, impacting proper combustion. A failing flame sensor or issues with the air-fuel mixture are also common causes. The detailed PDF guide advises homeowners to immediately contact a qualified technician for diagnosis and repair, prioritizing safety above all else. Ignoring these codes can lead to carbon monoxide buildup.
Error Code 11: Gas Valve Closure Error
According to the Noritz error code PDF, Error Code 11 specifically signals a “Gas Valve Closure Error.” This indicates the unit is detecting an issue where the gas valve isn’t opening or is unexpectedly closing during operation. This is a serious safety concern, potentially stemming from a faulty valve, wiring problems, or control board malfunction. The PDF explicitly warns against attempting any DIY repairs related to the gas valve.
This error prevents the burner from igniting, resulting in no hot water. The PDF emphasizes that troubleshooting requires a qualified technician to inspect the gas supply, valve functionality, and associated electrical components. Ignoring this error could lead to incomplete combustion and the risk of gas leaks, demanding professional intervention for a safe resolution.
Error Code 15: Ignition Failure Error
As detailed in the Noritz error code PDF, Error Code 15 signifies an “Ignition Failure Error.” This means the unit attempted to ignite the burner, but the process failed repeatedly within a set timeframe. Potential causes, according to the PDF, include a faulty igniter, insufficient gas pressure, or a problem with the flame sensor. It’s a common issue, but requires careful diagnosis.
The PDF advises checking the gas supply first, ensuring it’s fully open. However, it strongly cautions against attempting to repair the igniter or flame sensor without professional training. A technician will need to verify proper gas flow, inspect the igniter for damage, and test the flame sensor’s responsiveness to ensure safe and effective operation. Ignoring this error can lead to unburnt gas accumulation.
Error Code Range 21-30: Sensor & Component Failures
The Noritz error code PDF categorizes codes 21-30 as indicating failures within the unit’s sensor network and critical components. These errors often point to more complex issues requiring professional attention. The PDF highlights that these codes signal a problem with the system’s ability to accurately monitor and regulate its operation, potentially impacting performance and safety.
Common issues within this range include malfunctioning water temperature sensors, combustion air temperature sensors, and flow sensors. The PDF stresses that attempting self-repair of these components is not recommended due to the risk of further damage or safety hazards. A qualified technician possesses the tools and expertise to accurately diagnose the faulty component and restore the heater to optimal functionality, referencing the detailed schematics within the PDF.

Error Code 21: Water Temperature Sensor Error
According to the Noritz error code PDF, Error 21 specifically indicates a malfunction with the water temperature sensor. This sensor is crucial for accurately monitoring the water’s temperature as it passes through the heat exchanger, ensuring safe and efficient operation. The PDF details that this error can manifest due to a faulty sensor, wiring issues, or a problem with the control board’s interpretation of the sensor’s signal.
The PDF advises against attempting to replace the sensor without proper training, as incorrect installation can lead to further complications. It emphasizes the importance of a qualified technician using a multimeter to verify the sensor’s resistance and wiring continuity. Ignoring this error can result in scalding risks or inefficient heating, making prompt professional diagnosis, guided by the PDF’s troubleshooting steps, essential.

Error Code 24: Combustion Air Temperature Sensor Error
The Noritz error code PDF identifies Error 24 as a fault within the combustion air temperature sensor system. This sensor monitors the temperature of the air entering the combustion chamber, vital for safe and efficient gas burning. A malfunctioning sensor, as detailed in the PDF, can disrupt the air-fuel mixture, potentially leading to incomplete combustion or even a safety hazard.
The PDF stresses that this error shouldn’t be ignored, as it could indicate a blocked air intake or a failing sensor component. Troubleshooting, according to the PDF, requires a technician to check for obstructions and verify the sensor’s readings with specialized equipment. Attempting self-repair is discouraged due to the risk of carbon monoxide poisoning; professional intervention, guided by the PDF’s diagnostic procedures, is strongly recommended.
Error Code Range 31-40: Advanced System Errors
The Noritz error code PDF categorizes codes 31-40 as indicative of complex system malfunctions, often requiring specialized diagnostic tools and expertise. These errors move beyond basic operational issues, signaling potential problems within the unit’s control board, communication pathways, or intricate safety mechanisms. The PDF highlights that attempting DIY fixes within this range is strongly discouraged, as improper intervention could exacerbate the issue or create safety hazards.

According to the PDF, these advanced errors frequently involve internal component failures or communication breakdowns between multiple units in a linked system. The PDF emphasizes the necessity of a qualified technician to accurately pinpoint the root cause, utilizing the detailed troubleshooting flowcharts provided within the document. Ignoring these codes can lead to complete system shutdown or, in severe cases, compromise the unit’s safety features.
Error Code 31: Communication Error (Between Units)
The Noritz error code PDF details Error Code 31 as a “Communication Error,” specifically occurring between interconnected Noritz units – often in larger, multi-unit installations. This signifies a disruption in the data exchange vital for synchronized operation. The PDF stresses this isn’t a single unit failure, but a breakdown in how the systems ‘talk’ to each other, impacting overall hot water delivery.
Troubleshooting, as outlined in the PDF, begins with verifying physical connections between the units, checking wiring harnesses, and ensuring proper power supply to each component. The PDF cautions against assuming a faulty control board immediately; often, a loose connection or minor wiring issue is the culprit. A technician utilizing diagnostic tools can pinpoint the source of the communication failure, as detailed in the PDF’s advanced troubleshooting section.
Error Code 33: Freeze Protection Activation
The Noritz error code PDF identifies Error Code 33 as “Freeze Protection Activation.” This indicates the unit has detected temperatures nearing freezing and initiated its self-preservation protocols to prevent damage. The PDF explains this is a safety feature, not necessarily a malfunction, but requires investigation. It details how the unit circulates water or activates a heating element to maintain safe temperatures within the system.
According to the PDF, potential causes include extended periods of inactivity in cold weather, insufficient insulation of piping, or a malfunctioning temperature sensor. The PDF advises checking for frozen pipes and ensuring adequate heating in the installation area. Resetting the unit, as described in the PDF, may resolve the issue, but recurring Code 33 signals a need to address the underlying cause to avoid potential damage, as highlighted in the PDF’s preventative maintenance section.
Where to Find the Official Noritz Error Code PDF
The official Noritz error code PDF is a crucial resource for both homeowners and technicians. It’s readily accessible on the Noritz America website, typically located within the “Support” or “Downloads” section. A direct link is often provided in online forums dedicated to tankless water heater troubleshooting, ensuring easy access to the PDF.
The PDF itself is regularly updated to reflect changes in Noritz models and error code definitions. Searching online using specific keywords like “Noritz error code list PDF” will also yield results, but always verify the source to ensure you’re accessing the latest official document. Downloading the PDF allows for offline access, proving invaluable when internet connectivity is limited. Referencing this PDF is the first step in diagnosing any Noritz tankless water heater issue.
Resetting Your Noritz Tankless Water Heater
Attempting a reset is often the first troubleshooting step when a Noritz tankless water heater displays an error code. Typically, this involves locating the reset button on the unit’s control panel – consult your owner’s manual or the Noritz error code list PDF for precise location.
A simple press and hold of the reset button for a few seconds can often clear minor, temporary errors. However, it’s crucial to understand that resetting doesn’t resolve the underlying issue causing the code. If the error persists after a reset, it indicates a more significant problem requiring professional attention. Repeatedly resetting without addressing the root cause can potentially damage the unit, so proceed with caution and refer to the PDF for guidance.
When to Call a Professional
Despite the helpfulness of a Noritz error code list PDF and basic troubleshooting, certain situations demand a qualified technician. Persistent error codes after resetting, any gas-related concerns (like a gas smell), or codes indicating significant component failures necessitate professional intervention.
Attempting complex repairs yourself can void warranties and pose safety risks. A certified Noritz technician possesses the expertise to accurately diagnose the problem, safely repair or replace components, and ensure your water heater operates efficiently and safely. Don’t hesitate to call a professional if you’re uncomfortable or unsure about any aspect of the repair process – your safety and the longevity of your unit are paramount.


























