Viessmann · Mini-split
Fd Vapor injection outlet sensor fault
What the control is telling you
The enhanced vapor injection outlet temperature sensor is open or shorted. Shown on the 48K high heat model.
Applies to: DLCMHBH48EAK (48K high heat) only
Test and repair steps
- Safety kill power at the disconnect and wait for the inverter capacitors to discharge before touching boards or wiring.
- Check the sensor plug on the board and the wire for damage.
- Unplug the sensor and measure its resistance. T1-T4 sensors read about 10 kOhm at 77 F (25 C); the discharge sensor (T5/TP) about 54.9 kOhm at 77 F. Compare with the sensor resistance tables.
- Out of range or open/shorted replace the sensor. Sensor reads fine: replace the board it plugs into.
Models that show this code
7 models in Viessmann Vitocal 200-S DLCM(R/H)B multi-zone outdoor
Other codes on the same units
- FC Forced cooling
- Fb Vapor injection inlet sensor 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)
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Source: DLCMRBH/DLCMHBH Multi-Zone Outdoor Service Manual (sold as Midea, Carrier and Viessmann Vitocal 200-S; Viessmann doc 6225551-03, 12/2024), Table 24 Outdoor Unit Error Display (48 High Heat only) p.27; diagnosis p.51. 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.
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