HVACopedia

Midea · Heat pump

PC31 System low pressure protection

High severity Midea DLCURA ducted single-zone inverter heat pump (outdoor)

What the control is telling you

System low pressure dropped below the limit and the compressor stopped.

Applies to: DLCURAH18-60 AAK/ABK single-zone heat pump outdoor units (18K-60K, regular and High Heat)

Likely causes

  • Low refrigerant charge / leak
  • Service valve not fully open
  • Restriction
  • Poor airflow over the evaporating coil (indoor in cooling, outdoor in heating/icing)

Test and repair steps

  1. Warning: Turn off and lock out power at the outdoor disconnect and wait for the inverter capacitors to discharge before touching the outdoor board or compressor wiring.
  2. Confirm both service valves are fully open.
  3. Leak-test and check refrigerant charge.
  4. Check indoor airflow (cooling) or outdoor coil icing/defrost (heating).
  5. Check for line set or component restrictions.

Settings for these units

Save it for the next call

Star this code in the HVACopedia app and keep the whole library on your phone for jobs with no signal.

Open the app

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.