Navien Tankless Water Heater Problems And Its Solutions

Tankless water heaters have revolutionized the way we access hot water, providing a more efficient and space-saving solution for homes. However, as with any technological device, they can encounter issues. This article delves into the intricacies of Navien tankless water heater error codes, guiding you through Navien Tankless Water Heater Problems And Its Solutions common problems and their potential solutions.

How Navien Tankless Water Heaters Operate:

Tankless water heaters, also known as on-demand water heaters, provide hot water without the need for a storage tank. The process involves cold water flowing through a heat exchanger, which is then heated by either a gas burner or an electric element, delivering a continuous supply of hot water.

Also read: How To Convert Gas Water Heater To Electric?

Navien Tankless Water Heater Problems Error Codes:

Tankless water heaters are a modern and efficient way to ensure you have hot water on demand in your home. However, like all technology, they are not immune to problems. Understanding the various error codes that can appear on your tankless water heater is crucial to maintaining its performance and longevity. In this article, we will delve into four specific error codes – 016, 012, 11, and E004, exploring their meanings, common causes, and potential solutions.

Error Code 016: Heat Exchanger Issues

When your Navien tankless water heater displays Error Code 016, it’s indicating a malfunction within the heat exchanger. The heat exchanger is a crucial component, responsible for transferring heat from the burner or electric element to the water.


Calcification: In areas with hard water, minerals can build up over time, creating a calcified layer inside the heat exchanger. This not only hampers the efficiency of heat transfer but can also lead to overheating, and in severe cases, pinhole leaks.

Flow Sensor Issues: The error code can also arise from problems with the flow sensor, which might be impacted by the mineral buildup.

Also read: Why Is My Electric Tankless Water Heater Not Getting Hot Enough?


Descaling: For newer models or units that have been regularly maintained, a technician might perform a descaling procedure, using vinegar or a specialized descaling solution to dissolve and flush out the mineral deposits.

Part Replacement: In cases where the damage is more severe, parts of the heat exchanger or the entire unit might need replacement.

Preventative Measures: Installing a water softener in areas with hard water can help prevent future occurrences of this error.

Error Code 012: Flame Loss

Error Code 012 is a critical alert, as it signifies that the burner, which is essential for heating the water, is not igniting.


Gas Pressure Issues: Insufficient gas pressure can prevent the burner from igniting. This could be due to issues with the gas supply line or the gas valve.

Internal Leak or Fault: An internal component might be malfunctioning or there could be a leak within the unit.

Faulty Ignition Pack: The ignition pack, responsible for sparking the burner, could be faulty.


Gas Pressure Check: A technician will need to check and adjust the gas pressure if necessary.

Component Repair/Replacement: Any faulty internal components or leaks would need immediate attention and repair.

Ignition Pack Replacement: If the ignition pack is found to be faulty, replacing it should resolve the issue.

Error Code 11: No Ignition

This error code is displayed when the unit fails to ignite, a fundamental process for heating the water.


Earthquake Shutoff Valve Activation: Some units come with an earthquake shutoff valve, which might accidentally get triggered, cutting off the gas supply.

Dirty Gas Manifold: The gas manifold, responsible for controlling gas flow, might be dirty or clogged.


Valve Reset: If the earthquake shutoff valve is the cause, resetting it should solve the problem.

Manifold Cleaning: A technician will need to clean the gas manifold to ensure proper gas flow.

Gas Supply Check: Ensuring that there is a steady and sufficient supply of gas to the unit is also a crucial step in solving this issue.

Error Code E004: False Flame Detection

When Error Code E004 appears, it means that the unit is detecting a flame when there shouldn’t be one, indicating a sensor or circuitry issue.


Leak in Heat Exchanger: A leak in the heat exchanger could be causing this false detection.

Circuit Board Malfunction: The unit’s circuit board, responsible for controlling various functions, might be malfunctioning.

Exhaust or Intake Blockage: A blockage in the exhaust or intake could be interfering with the unit’s normal operation.


Leak Repair: Identifying and repairing any leaks in the heat exchanger is a priority.

Circuit Board Diagnosis and Repair: A technician will need to diagnose the circuit board and conduct repairs or replacements as needed.

Clearing Blockages: Ensuring that the exhaust and intake are clear from any blockages is also a crucial step in resolving this error.

Navien Flow Sensor Problems

When dealing with a lack of hot water from your Navien tankless water heater, one possible culprit could be a malfunctioning flow sensor. A straightforward remedy to attempt is opening and closing the pressure relief valve situated near the heater’s outlet, a method that often resolves this issue. If this doesn’t bring about a solution, it’s advisable to seek our professional services for an expert evaluation and repair of the sensor.

Particularly in older models of Navien tankless water heaters, the flow sensor may become susceptible to corrosion over time, leading to potential shutdowns of the heater. Addressing this issue could involve detaching the clamps, extracting the sensor, and performing a thorough cleaning. However, it’s important to note that this may offer only a temporary fix, and the problem is likely to reappear eventually. A more durable and effective solution would be to upgrade the sensor to a corrosion-resistant stainless steel version, ensuring a longer-lasting performance and reliability of your tankless water heater.


Navien Tankless water heaters offer a modern and efficient solution for hot water needs, but understanding and addressing potential error codes is crucial for maintaining their performance and longevity. By being aware of common issues and their solutions, homeowners can ensure the seamless operation of their Navien tankless water heater, enjoying uninterrupted hot water while reaping the benefits of energy savings and cost reductions.