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
- Disconnect one lead from the element and ensure it’s not touching anything.
- Set meter to AC Amps (20A+ range).
- 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.