Rheem Error Code C (upper case): Second-stage cooling (Heat Pump)

Updated October 15, 2026 · by Aurora Star Tech Inc.

Rheem error code C (upper case) on a heat pump means: Second-stage cooling. It is also called Rheem diagnostic code C (upper case).

Low severityHeat PumpRheem/Ruud PRL-JEC heat pump (Comfort Control2 ICC)

Homeowner? What Rheem code C (upper case) means for you

Usually minor Your heat pump is reporting: Second-stage cooling. This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.

Safe things you can check yourself

Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
In winter, keep snow and ice off and away from the outdoor unit. A short defrost cycle with steam is normal.
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Rheem error code C (upper case) mean?

Capital C steady on the display: the control is running second-stage (high) cooling. Normal.

Applies to: Rheem/Ruud PRL-JEC heat pumps with Comfort Control2 ICC

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Rheem models that use code C (upper case)

RPRL-024JEC RPRL-036JEC RPRL-048JEC RPRL-060JEC

Other Rheem Heat Pump codes

Code	Meaning
80	Low airflow
83	Condenser coil temperature sensor fault
84	Outdoor ambient temperature sensor fault
90	Communication fault
93	Internal control fault
c	First-stage cooling
d	Defrost active
d1	No shared data
d3	Airflow CFM mismatch
d4	Memory card invalid for device
d8	Old shared data
Defrost test (SW2)	Forced defrost test

All Rheem Heat Pump error codes →

Rheem code C (upper case): homeowner questions

What does Rheem code C (upper case) mean?

Second-stage cooling. Capital C steady on the display: the control is running second-stage (high) cooling. Normal.

Is it safe to keep using my heat pump with code C (upper case)?

Usually yes. Code C (upper case) is normally minor, but if it keeps coming back have it checked.

Can I reset Rheem code C (upper case) myself?

You can try one reset (power off for 30 seconds, then on). If Rheem code C (upper case) comes back, the cause is still there and a licensed technician should check it.

Who can fix Rheem code C (upper case) near me?

Aurora Star Tech Inc. repairs Rheem heat pumps in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

Troubleshooting guides

Bypass the 3-minute timer and clear a lockout with TEST (PRL-JEC) Rheem · Heat Pump
Force a defrost test (PRL-JEC) Rheem · Heat Pump
Heat pump will not defrost / incomplete or excessive defrost Rheem · Heat Pump
Insufficient cooling / pressure problems Rheem · Heat Pump
Outdoor fan runs but compressor does not Rheem · Heat Pump
Outdoor unit will not run Rheem · Heat Pump
Review or clear stored faults on the ICC display (PRL-JEC) Rheem · Heat Pump

Source: Rheem PRL-JEC Installation Instructions, Comfort Control2 section 12.3 and 12.6, pp.19-25. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.