High head pressure / unit cycling on HP

Refrigerant

AirCompDX - Field Reference for Air Compressor Techs
All HVAC symptoms
1

Dirty condenser coil

med
CheckVisual + delta-T across coil >30°F.
FixWash coil; comb fins.
2

Non-condensables (air) in system

high
CheckStanding pressure higher than saturation for ambient by >10 psi after long off-cycle.
FixRecover, deep evacuate to 500 µm, weigh in virgin refrigerant.
ToolsMicron gauge · Vacuum pump · Refrigerant scale
3

Overcharge

med
CheckSubcool well above target (typ. 8–12°F).
FixRecover slowly until subcool in spec.
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.