Viessmann Error Code nF: Filter replacement reminder (Mini-Split)

Updated October 16, 2026 · by Aurora Star Tech Inc.

Viessmann error code nF on a mini-split means: Filter replacement reminder. It is also called Viessmann diagnostic code nF.

Low severityMini-SplitViessmann DLFSHB high wall indoor

Homeowner? What Viessmann code nF means for you

Usually minor Your ductless mini-split is reporting: Filter replacement reminder. This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.

Safe things you can check yourself

Check the remote: fresh batteries and the right mode (Cool, Heat or Auto).
Check the breaker and the outdoor disconnect; both should be ON.
Open the front cover of the indoor unit and rinse the washable filters if they are dusty; let them dry before putting them back.
Keep the outdoor unit clear of snow, ice and leaves.
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Viessmann error code nF mean?

Time to replace the filter.

Applies to: DLFSHBH high wall indoor units 09-24K (Midea / Carrier / Viessmann) on DLC multi-zone or single-zone outdoor units

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Viessmann models that use code nF

DLFSHBH09XAK DLFSHBH12XAJ DLFSHBH12XAK DLFSHBH18XAK DLFSHBH24XAK

Other Viessmann Mini-Split codes

Code	Meaning
LC05	Speed limited by voltage
LC06	IPM high temperature / PFC frequency limit
LH00	Speed limited by indoor coil temperature
LH07	Speed limited by remote
LL	Controls locked
nA	No fault
ODU --	Outdoor board standby
ODU 00	Wiring / piping check finished
ODU CE	Automatic wiring / piping check running
ODU E0	Outdoor EEPROM error (outdoor board)
ODU E2	Indoor / outdoor communication error (outdoor board)
ODU E3	IPM to main board communication error (outdoor board)

All Viessmann Mini-Split error codes →

Viessmann code nF: homeowner questions

What does Viessmann code nF mean?

Filter replacement reminder. Time to replace the filter.

Is it safe to keep using my ductless mini-split with code nF?

Usually yes. Code nF is normally minor, but if it keeps coming back have it checked.

Can I reset Viessmann code nF myself?

You can try one reset (power off for 30 seconds, then on). If Viessmann code nF comes back, the cause is still there and a licensed technician should check it.

Who can fix Viessmann code nF near me?

Aurora Star Tech Inc. repairs Viessmann ductless mini-splits in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

Troubleshooting guides

Indoor unit leaking water All brands · Mini-Split
Poor capacity / high head All brands · Mini-Split
Water leaking All brands · Mini-Split
Discharge the inverter capacitors before service Viessmann · Mini-Split
Display shows a strange code or does not answer the remote - DLFSHB indoor Viessmann · Mini-Split
Multi-zone: one room heats, another will not cool - DLC multi-zone Viessmann · Mini-Split
Read live data with the outdoor check button (SW1) Viessmann · Mini-Split
Run the automatic wiring / piping correction Viessmann · Mini-Split

Source: Midea DLFSHBH09XAK indoor display table (photo, 2026-10-16); Carrier MS-DLFSHB-01 High Wall Ductless Service Manual (04/2021), Display Function p.12. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.