Spa powers on but will not heat, temperature stays below set point with no error code

Safety first: Turn off power at the breaker before opening the equipment bay.

• 1. Confirm settings:
  • Verify the set temperature is above current water temperature.
  • Ensure the spa is in Standard mode, not Economy or Sleep.
• 2. Check for heating indicator:
  • Look for a heater icon or indicator on the display when heating should be active.
• 3. Verify flow:
  • Clean filters and confirm strong circulation through heater return.
• 4. Inspect heater connections:
  • With power OFF, check heater terminals for loose wires or burn marks.
• 5. Test heater (technician):
  • A qualified person can measure heater resistance and voltage when heating is commanded.
  • If voltage is present but no heat, replace the heater assembly.
  • If no voltage is present, the heater relay or control board is likely faulty and should be replaced.