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Rheem · Heat pump

d3 Airflow CFM mismatch

Medium severity Rheem/Ruud PRL-JEC heat pump (Comfort Control2 ICC)

What the control is telling you

The indoor air mover (air handler or furnace) cannot supply the airflow the outdoor unit requests; shown on the thermostat and outdoor unit at startup.

Applies to: (-)PRL-JEC 2-stage 16 SEER heat pumps: RPRL/UPRL-024JEC, -036JEC, -048JEC, -060JEC

Likely causes

  • Wrong or undersized indoor air handler/furnace

Test and repair steps

  1. Confirm the indoor unit model is matched to the outdoor unit capacity.
  2. Replace with a properly sized air handler/furnace if misapplied.

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Source: Rheem (-)PRL-JEC Heat Pump Installation Instructions, 12.6 ICC Diagnostic Codes / 18.1 Serial Communicating System Initial Startup, p.29, 31, 42. 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.