E4
Luxaire
Evaporator Coil Freeze Protection / Low Evaporator Temperature
Luxaire air conditioner shows E4 and stops; may be accompanied by frost on the indoor coil or very low airflow.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Dirty air filter, Blower motor not running or running slowly, Low refrigerant charge, Thermostat set too low with poor airflow
How to Fix / Troubleshooting
Safety: Turn off power before removing blower or coil panels.
- Thaw the coil: Turn the system OFF at the thermostat and set the fan to ON. Let the blower run for 2–3 hours to melt ice on the Luxaire evaporator coil. Place towels under the air handler if accessible.
- Replace or clean filter: Install a new filter with the correct size and MERV rating recommended by Luxaire. Avoid overly restrictive filters.
- Inspect blower motor: With power off, spin the blower wheel by hand; it should move freely. Check for debris or a loose set screw. Restore power and verify the ECM or PSC blower motor starts smoothly. If it hums or fails to start, the motor or capacitor may need replacement.
- Check supply/return ducts: Open all registers and ensure returns are not blocked. Collapsed flex duct or closed dampers can cause freezing.
- Call a technician if freezing recurs: Persistent E4 after airflow corrections suggests low refrigerant or a faulty TXV. A pro must check superheat/subcooling and repair leaks.
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Repair Difficulty
Medium
3/5
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