HVACopediaMidea · Heat pump
PH91 Evaporator low temperature protection
What the control is telling you
The indoor coil temperature is too low (freeze protection, normally in cooling).
Applies to: DLCURAH18-60 AAK/ABK single-zone heat pump outdoor units (18K-60K, regular and High Heat)
Likely causes
- Low indoor airflow - dirty filter, blower problem
- Low refrigerant charge
- Low indoor load / low return air temperature
- Indoor coil sensor fault
Test and repair steps
- Check/replace the indoor filter and confirm the blower runs at the correct speed.
- Let the coil thaw if iced.
- Check refrigerant charge and leak-test.
- Check the indoor coil temperature sensor.
Settings for these units
Outdoor unit minimum clearances · Midea DLCURA ducted single-zone inverter heat pump (outdoor)
| Side | Minimum |
|---|---|
| A - top | 24 in. (610 mm) |
| B - right side (service side) | 24 in. (610 mm) |
| C - front (air outlet) | 24 in. (610 mm) |
| D - left side | 4 in. (101 mm) |
| E - rear (air inlet) | 4 in. (101 mm) |
| Above max snow depth | 2 in. (50 mm) |
Side letters taken from Fig. 8 drawing.
Units facing each other: 59 in. (150 cm) or more; do not blow into another unit's inlet.
Models that show this code
12 models in Midea DLCURA ducted single-zone inverter heat pump (outdoor)
Other codes on the same units
- PC40 Main chip to compressor-driver chip communication error
- PC42 Compressor start failure
- PC43 Compressor lack-phase protection
- PC44 Outdoor unit zero-speed protection
- PC45 Outdoor IR chip drive failure
- PC46 Compressor speed out of control
- PC49 Compressor over-current failure
- PH90 Evaporator high temperature protection
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Source: Midea/Carrier DLCURA Installation Instructions (Catalog DLCURA-03SI), Table 11 Outdoor Unit Diagnostic Codes, p.19. 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.