How to Tell if Your Hot Tub Heater Element is Bad

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Element with calcium scale -

If your breaker is tripping or your hot tub isn’t heating, you may have a bad heater element. We’ll walk you through the steps to determine if the cause of your problem is the heater assembly, heater element or another hot tub component.


Before getting started, it’s important to shut off all power to the hot tub at the service panel.

Tripped Breaker

To test if a bad heater is causing your tripped breaker, you can disconnect the copper tabs (or wires) from the spa pack to the heater element.

Disconnect power to the heater

Once disconnected, turn the power back on. If the breaker stays on, you’ve determined that the heater is bad. Find a replacement heater element.

Hot Tub is Not Heating

If your breaker is not tripping but your hot tub still isn’t heating, testing voltage to the heater using a multi-meter will help determine the cause.

Testing voltage

240V Spas

With the spa on, test both of the leads on the element at the same time. If the meter is reading 240v, the element is the problem. If the meter is reading zero, the problem is with the circuit board.

120V Spas

With the spa on, test both of the leads on the element at the same time. If the meter is reading 120v, the element is the problem. If the meter is reading zero, the problem is with the circuit board.

Alternate Testing Method

Another way to test for a bad heater would be an OHMs test, which checks the resistance of the element. To do this, follow these steps:

  1. Turn off all power to the hot tub
  2. Disconnect the copper tabs (or wires) going to the heater element.
  3. Set the multi-meter to the OHM setting
  4. Test both leads on the heater element

If the multi-meter shows 9-14 OHMs, the element is likely not bad. If the meter shows open, or reads nothing, the element is bad.

Replacing a Bad Heater Element

Once you’ve determined that the heater element is bad, you now need to decide if you need to replace just the element, or the whole heater assembly.

If the heater assembly is more than a few years old, it is best practice to replace the whole heater. Over time, corrosion and scale can deteriorate the heater assembly.

Need help finding a replacement heater or heater element? Email us a photo.


  1. Hi Keith,
    Thanks for the information. There are a couple of different things that could be going on here and a bad circuit board is a possibility. Before that conclusion can be made, I’m concerned that the pressure switch has been replaced, but the heater activates without pressure in the heater. That makes me think the switch may not be calibrated correctly (pressure switches are adjustable and cannot be factory preset). Give us a call when you have a moment near the tub and we’ll be happy to walk you through testing to see if that is the issue and further troubleshooting.



  2. Hi Brian! I filled the hot tub, flipped the breaker on and there is no more sparking noise from the circuit board. Primed and set it to heat and voila! The heater heated up the water fast and is working well. Thanks for all the troubleshooting tips!


  3. I have replaced my heater element and filled the tub flipped the switch and I have no heat, water is flowing through but the element is not getting hot. Is there anything else I could try?


  4. Hi Kyle,
    It sounds like the element isn’t receiving voltage. There are several reasons this could happen, so it’s best to give us a call when you have a few moments near the tub to troubleshoot.


  5. We have a Jacuzzi J335 Hot Tub. It is not heating. The OHMs on the heater element read 10.4. The circulation pump is working and the circulation switch is working. Could the heating element be bad even if it is getting power and the OHMs are correct?


  6. Hi Steve,
    If you can confirm the heater itself is getting full voltage (the incoming voltage from the service panel, 120V or 240V), and not working, you’ve confirmed the heater needs to be replaced. We’d love to walk you through troubleshooting the heater. Give us a call at 800-823-3638 and we’ll work with you.



  7. Hello
    The heater in my Caldera spa is not working. I have taken some readings and measurements and I am wondering if I could speak with someone there (perhaps Brian) who could help me. Thanks in advance


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