E5
Lennox · MPA012S4S Lennox Mini-Split Heat Pump System 12,000 BTU
Compressor drawing more current than safe limit. Causes: locked rotor (mechanically stuck), voltage too low/high, winding fault, or inverter board issue. Check supply voltage at outdoor disconnect — should be within ±10% of rated voltage.
Error E5 on the Lennox MPA012S4S Lennox Mini-Split Heat Pump System 12,000 BTU means: Compressor Overcurrent Protection. The top-ranked community fix is “Test and Replace Compressor or Inverter Board” (hard difficulty, ~90 min, DIY cost: $0-$20). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · mini split
Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.
While many mini split repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $400-$700.
Condensate Drain Blockage / Water Leak
Compressor High Pressure Protection
Indoor Coil Anti-Freeze Protection
Compressor Low Pressure Protection
Compressor Discharge Temperature Protection
Communication Error — Indoor/Outdoor
Indoor Fan Motor Fault
Indoor Ambient Temperature Sensor Fault
The Lennox MPA012S4S Lennox Mini-Split Heat Pump System 12,000 BTU has 8 other known error codes:
Ad Space — banner
Replace ADSENSE_PUBLISHER_ID in AdUnit.tsx