Coreco Prr Error Code
Carel RTN400 controller — Preheat alarm
Source: Coreco_rtn400_instruction_sheet_9is24288-1_rel0413_en_termostatos.pdf
What does Coreco Prr mean?
On the Coreco controller (Carel RTN400), Prr is preheat alarm: preheat input regulator ON; label Prr displayed, compressor icon blinking, regulation locked (compressor and fans).
Symptoms
- Display shows Prr
- Compressor icon blinking
- Regulation locked (compressor and fans)
Common causes
- Preheat input regulator active
- Preheat condition per the application configuration
Ask the AskWhiz AI about Coreco Prr
AskWhiz
online
Diagnostic steps
Recognise the preheat state
Prr means the preheat input regulator is ON and regulation is locked; confirm the preheat condition per the application.
When to call a professional
If the preheat alarm is unexpected, have a qualified technician review the application configuration.
Stop searching through PDFs. Our AI assistant on WhatsApp is trained on official Coreco documentation and can diagnose this fault code and guide you through the repair in minutes.
5 free questions per bot in your browser — no signup.
Other Coreco Error Codes
Control probe (probe 1) error — signal interrupted, short-circuited or incompatible probe
Evaporator / defrost probe (probe 2) error — signal interrupted, short-circuited or incompatible probe
Condenser / product probe (probe 3) error — signal interrupted, short-circuited or incompatible probe
Immediate or delayed alarm from the multifunction digital input (external alarm)
Open-door alarm from the door-switch digital input
Low-temperature alarm — measured temperature below set point by more than parameter AL
High-temperature alarm — measured temperature above set point by more than parameter AH
Unit parameter reading (data) error — saved configuration data error
Operating parameter reading (data) error — manual reset
Defrost ended by timeout — last defrost stopped on maximum duration, not on temperature
Defrost running — status message shown during a defrost cycle (not an alarm)
Dirty-condenser warning/alarm — pre-alarm (cht) between Ac-AE and Ac, then alarm (CHt) when Ac is exceeded and refrigeration stops (manual reset)
AskWhiz Playground
Test your diagnostic skills
Play a real HVAC service call in the AskWhiz Playground — real brands, real fault codes, no signup.
Play a real service call