Er4
Hayward
Internal Temperature Sensor Fault
Display shows Er4 and pump stops or fails to start.
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
Open or shorted temperature sensor on drive board, Damaged sensor wiring, Overheated components causing sensor drift, Control PCB failure
How to Fix / Troubleshooting
Safety first: Disconnect power at the breaker.
- Allow cooling: Let the pump sit powered off for at least 30 minutes to cool completely, then restore power and test.
- Inspect drive housing: Check for blocked ventilation, insect nests, or debris around the control end of the pump.
- Check for visible damage: If you remove the control cover, look for burned components or discoloration near the temperature sensor area on the PCB.
- Replacement: The temperature sensor is typically integrated into the drive board on Hayward variable-speed pumps. If Er4 persists, replace the drive/control module.
Advertisements
Repair Difficulty
Professional Required
5/5
Required Part
Drive Control Module
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements