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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.
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.
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:
- Turn off all power to the hot tub
- Disconnect the copper tabs (or wires) going to the heater element.
- Set the multi-meter to the OHM setting
- 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.
Hot Tub Blog | SpaDepot.com 
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.
Thanks,
Brian
SpaDepot.com
800-823-3638
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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!
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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?
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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.
Thanks,
Brian
SpaDepot.com
800-823-3638
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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?
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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.
Thanks,
Brian
SpaDepot.com
800-823-3638
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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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Hi Dennis,
Please call us at (800) 823-3638. One of our techs will troubleshoot with you.
Thanks,
Sarah
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Hi my hot tub is not heating to set point any ideas I have checked water level and changed filter it on 36.6 Sunday when I uncovered to get a dip and trying to heat up I turned off as going nowhere got up and turned back on was 34.4 still on that after 6 hrs any thoughts please?
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Hi Louise,
If the heater element is getting service voltage to it and the water isn’t heating up, you have a bad heater element. Give us a call and we’ll be happy to troubleshoot with you.
Thanks,
Brian
SpaDepot.com
800-823-3638
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I have a 240v tub and the last gfi burnt up. Replaced that and the hot tub comes on but as soon as the heater kicks on it trips the 50amp gfi. I have 240v going to the element and 16ohms and it’s not grounding out to the housing…. if I unhook the heating element it will not to breaker. My question is how can the heating element test good and still to the breaker?
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Hi John,
It can be tricky to test the element accurately. Indeed, I have tested elements that I proclaimed to be good, yet once they were put into use, turned out to be bad (embarrassing). Anyways, simply replace your element and you’ll be good to go!
Thanks,
Brian
SpaDepot.com
800-823-3638
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I have a 2007 Vita Spa that is not heating. With the leads removed from the heating element, I measure 19 ohms which is good. If I connect meter to the disconnected leads and apply power I get 233volts. If I connect the leads to the heater and apply power I get ZERO Volts, even when the relay is eneregized. No fuses are blowing.. this feels like am AMP problem.. any ideas ?
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I have a hydro pool serenity hot tub. I have the temp set to 102 but it will only heat up to 92. Any suggestions. I cleaned the filter and reset the power a couple of times no luck. The up arrow for the temp is on.
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Hi David,
One last thing to try before doing a voltage test at the heater, try running with the filter removed and see if there’s any change. Sometimes an otherwise clean-looking filter can actually be plugged enough to reduce flow. If that doesn’t work, you’ll want to test and see if you’re getting service voltage across the heater terminals when the tub calls for heat. I’d be happy to walk you through that when you’re ready, just give me a call.
Thanks,
Brian
SpaDepot.com
800-823-3638
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Hi Ron,
I think the full story will be revealed when you reconnect power to the heater. When the tub calls for heat, and the heater should kick on, do you indeed get 240V across the 2 heater terminals? If so, and the tub isn’t heating, despite what resistance you’ve measured across the element, the heater is bad. If you don’t get proper voltage, there is a different problem down up the line that we’ll want to troubleshoot with you. Just give us a call and we’ll help with the diagnosis.
Thanks,
Brian
SpaDepot.com
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