Fault Code Lookup

HVAC Sales Master
A957_O
Low Refrigerant Pressure (latched alarm)
This code typically points to
  • Low-charge / airflow / EXV / restriction family

Next checks to confirm
  1. Evaluate low-pressure cause
  2. Same low-suction-pressure section applies as 21L

Escalation
4-hour lockout
Reset behavior
Automatic after lockout interval if fault clears; hard numeric 21L logic may still apply in repeated cases.
Urgent
Fix now
Source
Rheem RP18AZ Installation Instructions Table 15 and low-suction-pressure section