E04
Emaux
Control PCB Fault / Internal Electronics Error
Pump display shows E04 and the motor does not run, often after a power surge or lightning event.
Advertisements
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.
Advertisements
Possible Causes
Damaged control PCB due to surge, Corrupted firmware on variable-speed controller, Internal relay failure on control board
How to Fix / Troubleshooting
Safety first: Disconnect power at the breaker before opening the control box or motor terminal cover.
- Power cycle the unit: Turn off the breaker for 5 minutes, then restore power and attempt to restart the pump. Sometimes transient faults clear after a full power reset.
- Inspect control PCB: Open the Emaux control module (if user-accessible). Look for burnt components, bulging capacitors, or scorch marks. If any are present, the PCB must be replaced.
- Check surge protection: Verify that the pump is connected through a proper surge protector or that the pool equipment subpanel has surge protection installed. Add protection if absent.
- Do not bypass safety circuits: Never attempt to bridge relays or bypass the PCB; this is unsafe and can damage the motor or cause fire.
In most cases, E04 requires replacement of the Emaux control PCB or complete motor/control assembly by a qualified technician.
Advertisements
Repair Difficulty
Professional Required
5/5
Advertisements