e4
Moderate
Daikin · Mini-Splits & Ductless Systems
Low Pressure Fault
Quick Answer
Error code E4 on your Daikin Mini-Splits & Ductless Systems means: Low Pressure Fault. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Check indoor filters and coil for ice buildup; thaw if frozen before diagnosing further
2
Inspect line set connections for oil stains indicating refrigerant leaks
3
Connect gauges and measure suction and discharge pressures
4
Perform a leak test on all accessible connections and coils with an electronic leak detector
5
A licensed HVAC technician must perform leak repair and refrigerant charging per EPA regulations
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Refrigerant (R-410A or R-32 depending on model)
Expansion valve
Leak repair materials (brazing rods, nitrogen)
Low-pressure switch
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