Fault Code Lookup

HVAC Sales Master
19
Low Pressure Switch Open
This code typically points to
  • Low charge
  • Restricted indoor airflow
  • Low load conditions
  • Refrigerant-side issue

Next checks to confirm
  1. Verify actual refrigerant conditions
  2. Verify airflow before condemning switch

Escalation
Repeated trips with verified airflow indicate refrigerant issue.
Reset behavior
Self-clears when pressure recovers; repeated trips may lock out.
Urgent
Fix now
Source
iQ Drive Table 7