HVACopediaNavien · Combi boiler
E441 DHW outlet 2 sensor fault
What the control is telling you
The second domestic hot water outlet thermistor is open or shorted. NFC-H manual lists the reset type as: Auto reset.
Applies to: Navien fire-tube combi boilers, NFC-H series (NFC-250/200H, NFC-250/175H) and NCB-H combi boilers (NCB-250/150H, NCB-240/130H, NCB-240/110H, NCB-190/080H, NCB-190/060H)
Likely causes
- Sensor wiring
- Failed thermistor
Test and repair steps
- Check Status Information > 10. Outlet 2 Temp.
- Power off and check the sensor connector and wiring.
- Code keeps returning? Phone Navien Technical Support, 1-800-519-8794.
Settings for these units
- Minimum installation clearances (indoor) · Navien NCB-H
- Water quality limits (DHW and system fill) · Navien NCB-H
- Minimum installation clearances (indoor) · Navien NFC-H
- Water quality limits (DHW and system fill) · Navien NFC-H
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Source: Navien NCB-H Installation & Operation Manual, 11.7 Understanding Error Codes, p.129-130; Navien NFC-H Installation Manual, 11.7 Understanding Error Codes, p.127-128. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.