Navien Error Code E441: Dom.Hot Water Outlet2 Sensor

Severity
Warning
Type
digital display
Estimated repair cost: $100 — $250 (parts + labor)
Warning: The Navien tankless water heater has shut down due to a problem with the domestic hot water outlet temperature sensor. This will prevent hot water production until the issue is resolved.

How to Fix Navien Code E441

  1. Step 1: Power cycle the unit by turning off the power switch for 30 seconds, then turn it back on. This may reset the system and clear a temporary error.
  2. Step 2: Check the sensor wires that are visible without opening the unit. Look for any obvious damage or loose connections.
  3. Step 3: If the error persists after power cycling, contact a qualified HVAC technician to diagnose and repair the issue.

How to Reset Navien Code E441

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Navien Error Code E441 Mean?

The E441 error code on your Navien tankless water heater indicates a problem with the DHW Outlet 2 sensor. This sensor monitors the temperature of the hot water as it leaves the unit. The Navien control board uses this temperature reading to regulate the burner and maintain a consistent hot water temperature. If the control board receives an unusual or no signal from this sensor, it will display the E441 error and shut down the unit to prevent potential overheating or other issues. This shutdown is a safety feature to protect the unit and your plumbing system. Specifically, this error means the control board is seeing either an open circuit, short circuit, or a reading outside the acceptable range from the DHW Outlet 2 sensor. This could be due to a faulty sensor, wiring issues, or even a problem with the control board itself. Because the unit relies on accurate temperature readings to operate safely and efficiently, it's important to address this issue promptly.

Common Causes

  • Faulty DHW Outlet 2 sensor
  • Wiring issue (loose connection, damaged wire) between the sensor and the control board
  • Corrosion on the sensor or connector pins
  • Sediment buildup on the sensor affecting its accuracy
  • Control board malfunction

Diagnostic Steps

If... Check Expected
Unit displays E441 error Measure the resistance of the DHW Outlet 2 sensor at the control board connector Resistance should be within the range specified in the Navien service manual for the measured water temperature. (Typically around 10k ohms at room temperature)
Sensor resistance is out of range or open circuit Inspect the wiring harness and connector pins for corrosion or damage Wiring and connectors should be clean and in good condition
Wiring appears OK Check the voltage at the sensor connector on the control board (with the sensor disconnected) Should be a stable DC voltage (typically 5VDC)
Voltage is present and stable, but sensor resistance is incorrect Replace the DHW Outlet 2 sensor Error code clears and unit operates normally

Applicable Navien Models

Source Documentation

Referenced in 2 official Navien technical manuals.

ManualPageReasonAction
Navien NCB-H Installation & Operation Manual129Dom.Hot Water Outlet2 SensorContact technical support at 1-800-519-8794.
Navien NFC-H Installation & Operation Manual127Hot water outlet 2: thermistor open or short circuitAuto RESET

Replacement Parts

Part OEM Number Est. Cost Where to Buy
DHW Outlet 2 Temperature Sensor 30012345A
Main Control Board PCB-NR240A

Related Codes on Same Models

Other codes that affect the same Navien model families as E441.

Code Description Severity
E001 Ignition Failure Warning
E003 Abnormal Ignition Warning
E004 False Flame Detection Warning
E012 Flame Loss Warning
E016 Overheating Warning
E030 Exhaust Overheat Sensor Warning
E031 Inlet Thermistor Open/Short Warning
E046 Outlet Thermistor Open/Short Warning
E047 DHW Thermistor Open/Short Warning
E060 Fan Motor Abnormality Warning