How to Tell if Your Hot Tub Heater Element is Bad

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Bad heater element

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. Need a new motor for a drem maker spa water way is what’s in there now how do I know which one to pick


  2. Hello,
    We have a Marquis Everyday Spa that was already here when we purchased the house.
    In trying to get it to work, I tested power at the 50 amp GFCI breaker and found that the breaker was getting 240V from the service panel but not from spa side of the breaker.
    I replaced the breaker and it still does not supply power on the spa side of the breaker, nor does the breaker trip properly when pressing the “Test” button on the breaker.
    Is there anything with the spa that could cause this such as a bad heater element, missing filters, or some sort of reset button in the spa, etc?
    Thanks for your assistance.


  3. Hi Roger,
    GFCI breakers can be tricky to install, even for experienced electricians. The symptoms you describe lead me to believe there may be an issue with the wiring of your breaker. We do have a handy guide that covers GFCI breakers, found here:
    We would be happy to look over your wiring to ensure it is correct. Please send us a clear photo of the inside of your GFCI panel to, and our technicians will assist you.


  4. What if you have 120V to ground on one leg of the copper straps that connect to the heater and only 25V on the other? Also, if you connect them, they trip the breaker. I’ve checked input voltage and I have 240V across and 120V from each leg to ground. Bad board?


  5. Hi Benjamin,
    You could have a circuit board that needs to be replaced, though rather than measuring from either terminal to ground, you should measure voltage across both terminals. I suspect you’ll find you have zero voltage.
    In this instance, before you replace the entire circuit board, I’d replace the heater element with our BX5000. Carefully evacuate the air from your plumbing before powering up. Now, once you have a good element in there, and the tub calls for heat, you should get 240V across both element terminals.


  6. I have a Balboa Control System, model MAS560, with M7 heater. It’s a 240 volt system. With power on and the control panel showing the heater on, I get zero volts across the heater terminals. Either terminal to ground measures 120 volts. It sounds like this is a mother board problem. Any way to test the relays? I cannot find a pinout for them.


  7. Hi Mike,
    If you’re getting correct voltage to the board, and no error codes to on the topside display, you should be getting service voltage across the element terminals. Lack of voltage across the terminals would indicate a bad circuit board. In that case, you’d replace the whole circuit board. Balboa, manufacturer of your board, does not, and will not release any engineering diagrams of their boards to simply replace components on the board, so board replacement is the only option.
    Please give us a call if you would like to speak with one of our hot tub technicians.
    (800) 823 3638 M-F 6am-5pm


  8. I followed your test above and I am confused I removed the copper tabs and breaker stays on. I then tested the OHM’s on the heater and it read 3. I then tested voltage on both the tabs and heater posts and got 0. I am confused because of the low ohm reading and the fact that the circuit breaker stays on after disconnecting tabs. If I reconnect the tabs the breaker trips.


  9. Hi Andy,
    Thanks for your comment. In order to help you best, I would suggest that you give our technical team a call. They will be able to walk you through testing your heater element.
    (800) 823 3638 M-F 6am-5pm Pacific


  10. Hi Mike,
    Good heater elements will have a resistance value of between 9Ω and 16Ω, and no continuity to ground. If your heater meets those criteria, it’s likely good. If you have continuity to ground, it’s definitely bad.
    If you need further assistance determining why your spa is not heating, please feel free to give our technical department a call.
    (800) 823-3638 M-F 6am-5pm Pacific


  11. Hi I have Balboa 2000 AMT10 Pack 5.5kw heating element not heating that test good for continuity and doesn’t trip GFI but I onlt get 50V AC across the element terminals s/b 250v. If it is a bad mother board what should I look for to indicate this problem. Any help much appreciated


  12. Hi Pau,

    You could look for any burned spots on the front or back of the board, but really, if you’re only getting 50V to the heater and you’re not getting any error codes on your topside controller, a replacement circuit board is in order.



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