Danfoss VLT HVAC Drive FC 102
Danfoss VLT HVAC Drive FC 102 code 23: Internal fan fault
A protective warning indicates that the internal fan is either not running or not mounted properly.
- Code
- 23
- Name
- Internal fan fault
- Controller
- Danfoss VLT HVAC Drive FC 102
- Type
- General fault
- What it does
- Warning: the equipment keeps running and flags a problem
- Risk
- GREEN In your wheelhouse
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
Subscribers get:
- What to do next, in plain words
- What the manual says to do, and the page it is on
- Booking a live video call with Ben, a master booth technician ($250/hr, paid per call)
Questions about this code
What does Danfoss VLT HVAC Drive FC 102 code 23 mean?
A protective warning indicates that the internal fan is either not running or not mounted properly.
Is Danfoss VLT HVAC Drive FC 102 code 23 dangerous?
It is graded green: in a working tech's wheelhouse with standard tools and low risk.
How do I fix Danfoss VLT HVAC Drive FC 102 code 23?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.
Other Danfoss VLT HVAC Drive FC 102 codes
15 · Hardware mismatch16 · Short-circuit17 · Control word timeout18 · Start failed24 · External fan fault25 · Brake resistor short-circuit26 · Brake resistor power limit27 · Brake chopper fault28 · Brake check failed29 · Heatsink temp
All 73 Danfoss VLT HVAC Drive FC 102 codes · Every fault code