Safety First: Always turn off the breaker before touching wiring or heater connections. Only turn it on when testing live voltage/amps and handle with extreme care.


1. Test Voltage to the Spa Pack

Meter setting: AC Volts

  • Red to black: ~240V
  • Red to white (neutral): ~120V
  • Black to white: ~120V

If readings are low or zero: Check incoming power supply or wiring before testing the heater.


2. Test Heater Element Resistance (Ohms)

Breaker: OFF
Meter setting: Ohms (Ω)

  • 4 kW element: ~14Ω
  • 5.5 kW element: ~10Ω

If reading is zero or way off: Likely a failed element—confirm with other tests before replacing.


3. Test Continuity

Breaker: OFF
Meter setting: Continuity (beep mode)

  • Touch probes to element terminals.
  • Beep = continuity present
  • No beep = replace element


4. Test Voltage at the Heater Element

Breaker: ON
Meter setting: AC Volts

  • Carefully touch probes to the two element terminals.
  • Expected: ~240V for a 240V system.

If voltage is zero: Replace the element or check control board.


5. Test Amps (Most Accurate Test)

Breaker: OFF

  1. Disconnect one lead from the element and ensure it’s not touching anything.
  2. Set meter to AC Amps (20A+ range).
  3. Breaker ON—carefully complete the circuit using meter probes.
  • 4 kW element: ~16–17A
  • 5.5 kW element: ~22–23A

If amps are zero: Replace the element.


6. If All Tests Pass but Heating Is Weak

  • Check for calcium buildup on the element (can slow heating).
  • Look for error codes (may indicate sensor or board issues).
  • Consider possible control board failure if all readings are normal.