1
High-pressure safety tripping
highCheckDirty condenser, condenser fan failure, overcharge.
FixClean coil, replace fan/cap, recover and weigh in correct charge.
2
Low-pressure safety tripping
highCheckLow charge, restricted filter-drier, blocked TXV.
FixRepair leak; replace drier and recharge; replace TXV if metering fails.
3
Thermostat differential too narrow / bad location
lowCheckStat in supply airflow or direct sun.
FixRelocate stat or widen swing/anticipator.
Safety
Pull the disconnect and lock out before opening HVAC equipment. Discharge dual-run capacitors before handling. Refrigerant recovery and brazing require EPA 608 certification and proper PPE.
