Control panel displays E04 and the system will not run
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.
Possible Causes
How to Fix / Troubleshooting
Safety first: Do not attempt to run the spa if the water or hoses are frozen. Ice can damage the pump and heater.
- Check environment: Confirm that the outdoor temperature is within Bestway's specified operating range (typically above 4–5°C / 39–41°F).
- Inspect for ice: Gently squeeze hoses and spa walls to check for ice formation. If frozen, allow the spa to thaw naturally in a warmer environment. Do not use open flames or high heat.
- Warm the control unit: If only the control unit is very cold, you can temporarily insulate it or use a safe, indirect heat source nearby (not touching) to bring it above freezing.
- Power cycle: Once thawed and above freezing, unplug the spa for 10 minutes, then reconnect and attempt to clear E04.
If E04 persists in normal temperatures, the temperature sensor or control board may be misreading and require professional diagnosis and replacement.
Repair Difficulty
Required Part
We may earn a commission from links on this page.