Daikin Error Code E4: Low Pressure Switch Activated
Warning: Your Daikin HVAC system has experienced a low pressure issue, which could lead to system damage if not addressed.
How to Fix Daikin Code E4
- Check your air filter and replace it if it's dirty.
- Inspect the area around your outdoor unit for any signs of refrigerant leaks, such as wet spots or a hissing sound.
- If you suspect a refrigerant leak, contact a professional HVAC technician immediately.
How to Reset Daikin Code E4
- Turn off the unit using the remote control or wall controller.
- Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
- Restore power at the breaker.
- Turn the unit on with the remote control. If the error returns, the fault needs professional diagnosis.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Daikin Error Code E4 Mean?
The E4 error code on your Daikin HVAC system indicates that the low pressure switch has been activated. This switch is designed to protect your system from operating at pressures that are too low, which can cause damage to the compressor and other components. The most common causes for this error are refrigerant leaks, clogged filters, or issues with the expansion valve.
Common Causes
- Refrigerant leak
- Clogged air filter
- Faulty expansion valve
- Kinked or damaged refrigerant lines
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| System is not running | Inspect the air filter and replace it if necessary. | Clean air filter |
| System is running | Measure the suction line temperature and pressure. | Normal suction line temperature and pressure (consult Daikin's technical manual for specific values) |
Applicable Daikin Models
- Daikin Comfort(electric)
- Daikin Fit(electric)
- Daikin Intelligent Touch(electric)
- Daikin Latitude(electric)
- Daikin Unitary System(electric)
- FIT(electric)
- Inverter Ducted Split System(electric)
- LV Series(electric)
- MXS(electric)
- Multi-Zone(electric)
- NCB(electric)
- NCM(electric)
- NCV(electric)
- NCW(electric)
- NMB(electric)
- NMP(electric)
- NPE(electric)
- NTV(electric)
- NW(gas)
- NWZ(dual_fuel)
- Quaternity(electric)
- SkyAir(electric)
- VRV(electric)
- VRV IV(electric)
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Low Pressure Switch | 45112C1001 | — | Find Part |
| Expansion Valve | — | — | — |
Related Codes on Same Models
Other codes that affect the same Daikin model families as E4.
| Code | Description | Severity |
|---|---|---|
| A1 | Indoor PCB Defective | Warning |
| A3 | Drain Level System Fault | Warning |
| A5 | Freeze-Up/Overheat Protection | Warning |
| A6 | Fan Motor Lock/Overcurrent | Warning |
| C4 | Heat Exchanger Thermistor Fault | Warning |
| C9 | Suction Air Thermistor Fault | Warning |
| E1 | Outdoor PCB Defective | Warning |
| E3 | High Pressure Switch Activated | Warning |
| E5 | Compressor Motor Lock | Warning |
| E6 | Standard Compressor Motor | Warning |