How to Tell if Your Hot Tub Heater Element is Bad

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Element with calcium scale - SpaDepot.com

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.

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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.

95 comments

  1. Hi Frank,
    Your heater element very likely is shorting, and needs to be replaced. Try testing the element for continuity to ground. Place one of your meter probes on one of the element terminals, and the other probe to the heater manifold (if the element is removed from the manifold, place the probe on the element sheath). You should find no continuity, though you probably will. If you have any questions while you’re working on it, give us a call and we’ll walk you through it.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  2. The breaker tripped a few times and now the blue “Ready Light “ is off.The hot tug has water movement and is staying at 96 degrees but no hotter. I replaced the heater 3 years ago with the Watkins 6 k no fault and it worked great. Is it the heater/ or sensor/ is three years the life of the heater.

    Like

  3. Hi Mike,
    The NoFault heaters are actually quite robust, and have a long lifespan. It’s more likely on an IQ2020 control system that the heater control board is causing the issue. The heater control board is probably not sending voltage out to the heater and should be.

    Double check the heater though, just to make sure it’s good, by testing resistance through the white and black wires. You should find 9Ω – 15Ω resistance. Next, check from the white wire to the green wire. You should find no continuity. If those things check out, the heater is good.

    When you’re ready to test, give us a call at 800-823-3638 and we’ll walk through the testing together.

    Thanks,
    Brian
    SpaDepot.com

    Like

  4. I’ve got a 2005 Solana TX. Temp has dropped to around 96 ish even though the control panel is set at 104. I’ve removed the filter and ran it without for a couple of days but the temp never increased. I get no continuity from the heater element to ground and if I’m reading my meter correctly, I get 14.3 ohms. I think the heating element is ok, do you agree? If it is, what could be the problem?

    Like

  5. Hi Dan,
    If those are the readings you’re getting on the heater, it is indeed good. The next step is to see if the heater is getting voltage. Measure across the two hot lines to get your reading. I suspect you’ll find zero volts, which means you’ve probably got a bad heater relay board. When you’re ready to check, give us a call at 800-823-3638 and we’ll go through it together.
    Thanks,
    Brian
    SpaDepot.com

    Like

  6. Thanx for the quick reply Brian…..it holds steady at 96ish, wouldn’t that mean that I have voltage….or at least some?

    Like

  7. Hi Dan,
    Not necessarily. Friction from the pumps running can keep the tub warm-ish. Give us a call and we’ll walk through it together and get you set up.
    Thanks,
    Brian
    SpaDepot.com

    Like

  8. Just prior to me finding this site, I drained the tub and removed the heater. At this point, I won’t do anything to it until late summer early fall. I will bookmark this site and make contact with you when I refill. Thanx Brian for the info….I’ll be in touch

    Like

  9. I’ve got a dream maker spa, connected to 110v. It doesn’t heat to tub much beyond 80 degrees F with it set to 105. Have the heater removed and am reading 17 ohms across the element with no shorting to ground.

    Manifold has the heater element pressed in through holes to the outside and sealed with what looks like red silicone sealent. There are spade connectors tacked to the element pins on the outside of the manifold inside a removable clear plastic cover.
    The manifold has a label with the following:
    S/N 58206-011602230235
    HEATER 4.0KW 240V / 1.0KW 120V 10″

    Before I go trying to find schematics for this and continue the process, could it be as simple as a failing element?

    Like

  10. Hi Steve,
    If you’re measuring 17Ω across the element, it’s probably still good. I would actually measure voltage across the element leads with the tub calling for heat. You should find 120V. I suspect you’ll find 0V. If you find no voltage, there’s a problem with the circuit board. Please phone our technical department at 800-823-3638 when you’re ready to test for voltage. We’d love to be able to troubleshoot with you.

    Thanks,
    Brian
    SpaDepot.com

    Like

  11. Hi I’ve got a Balboa gs100 and ive just filled it up after the winter but it doesn’t seem to want to hear up. Been on for 48 hours in total and it’s at 16c (Scotland) i tried a few things for air locks but I don’t think it’s an air lock as all jets and circulation pumps are working fine. Am going to test the heater today with am muiltimeter but wondering if there is anything else to check or to other causes. Hot tub is only 2 years old.

    Like

  12. Hi James,
    Before testing the heater, test to see if the heater gets service voltage when the tub is calling for heat. If it does not, your problem is with the control system.

    Thanks,
    Brian
    SpaDepot.com

    Like

  13. Hi Brian, I have similar issues with my hit tub not heating. I followed your instructions. While the jets on I did measure for voltage between the heater leads. I got 116 Volts. I turned everything off.. removed the power, disconnected the heater leads and measured for ohms. It read 14 ohms. Still not heating. Any other suggestions?

    Like

  14. Hi Francisco,
    Assuming your spa service voltage is 120V, and not 240V, it sounds like you’re getting voltage to the heater, and the element is good. It’s important to recognize that spas utilizing 120V heaters will heat at most 1°/hr, and often times, less. That means, you’re going to have to wait several hours before seeing an increase in heat. Why not give our technical department a call at 800-823-3638 when you have a moment near the tub and we can explore what’s going on with your spa in more detail.

    Thanks,
    Brian
    SpaDepot.com

    Like

  15. I have a durasport strong spa. We have a few weird things going on and they all started at the same time. Since the last time we drained and refilled the spa it now runs on low but trips the breaker when we try the jets. We bled out all the air, it started working. Now every time we go to use the hot tub and try the jets they wont come on and trips the internal GFI. I was told possibly a heater core going bad. If we plug it in to a stronger Wall plug it will run without tripping the fuse.(if we get the jets to work) We have it hooked into a 20 amp fuse plug normally. When this all started, the OH warning comes on the panel and the water is super hot 110 degrees and runs all the time. (on low). Our repair man came out and plugged it in and it worked immediately. He stated with the problems we are having (he couldnt verify) sounds like the heater core going bad. Can you give me your thoughts….

    Like

  16. Hi April,
    If the spa is heating normally, I would say your pump is more likely to be causing the breaker to trip. Based on your description though, it sounds like everything is kind of working sporadically. We’re happy to walk through this issue with you over the phone, and make sure you get exactly what you need to fix your spa right the first time. Simply call us at 800-823-3638 6a-5p Pacific Monday – Friday.

    Thanks,
    Brian
    SpaDepot.com

    Like

  17. I have an Intex purespa bubble massaging tub. My pump is throwing an e95 error meaning the tub is overheating but the tub is kicking off at 96*. How do i test either the sensors or the heating element?

    Like

  18. Hi Dominic,

    Overheating heaters are usually caused by a reduction in water flow. Start by removing the filter and seeing if the trouble stops or is reduced. If it’s reduced but not stopped, the next thing to do is make sure the pump is in good working order. In the case of an inflatable spa, there’s not much you can do to test beyond that, since no individual parts are available. You’ll simply have to replace the entire control system. If you run into questions, give us a call at 800-823-3638 and we’ll be happy to talk with you while you’re working on the spa.

    Thanks,
    Brian
    SpaDepot.com

    Like

  19. Hey i have a coleman thruma spa. Was tripping the breaker. Pulled out the heating unit and one of the single cartridge heating elements is toast. Cant seem to find out what wattage heating element to replace it with. Its a 110/120 volt. Theres 2 of them in there. There like 9 and 1/2 inch long 1/2 inch diamter. So they make from 100 watts to like 750 watts. Any help would b appreciate.

    Like

  20. Hi Travis,

    We’re happy to help you find the correct wattage. Please email (help@spadepot.com) us a photo of the current heater for identification. We’ll make sure you get the replacement you need.

    Thanks,
    Brian
    SpaDepot.com

    Like

  21. Hi the minute the electronics call for heat, I see a 31AC code on the control panel otherwise the tubworks fine. ACC who are the actionpack , are stumped. Any ideas?

    Like

  22. Hi Todd,

    It’s probably either a high limit warning or a pressure switch operating incorrectly, both of which would be due to a flow restriction. Try removing the filter from the spa and see if you get the same warning. If not, replace your filter and try again. If you do get the warning, give our technical department a call at 800-823-3638 when you have a moment near the tub and we’ll be happy to help troubleshoot with you, in real time.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  23. Bill
    i have a leisure bay spa with the ener-g-smart control package 2 pumps my breaker just starting tripping i have narrowed it down to the heater witch is a ..HTR 4.0KW 240V Leisure bay 58042 the two heater white heater wires when i om out shows 15.6 but the screw terminal on the top of where the one wire goes shows some signs of smoke or arking would it be that the board heater output is bad or the heater

    Like

  24. Hi Bill,
    Try testing for continuity from one of the white wires to the heater tube itself. If that’s open, you may have a problem with your circuit board. Give us a call at 800-823-3638 when you’re ready to test, and we’ll go through it together real-time.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  25. Hi,
    I just replaced the heater, so I know that is good, but I’m not getting 240V across the wires. I do get 120 from one lead to ground (I don’t know if that means anything). Could I have a relay issue? The Spa is an Arctic spa (with the old on the board style relays).

    Like

  26. Hi Tim,
    If you can’t get 240V across the two element terminals when the tub calls for heat, you indeed have a relay problem. If you’re particularly handy, you can un-solder the relays and replace them, but most people would replace the circuit board or control system altogether. We can help you decide what’s best, just give our technical department a call when you have a moment.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  27. Stumped! Have 2004 Sundance Bahia that suddenly began to trip the breaker. Went through the process of unplugging all the items from the board, plugging in one at a time and all worked well until I got to the heater. The breaker tripped immediately when the system called for heat. I installed a new heating unit (by-pass) and went through the same procedure with same result (breaker tripped as soon as system called for heat). I have unplugged the new heater from the board and the tub is running as normal. Not sure what may be causing this issue. Any guidance would be helpful.
    Dave

    Like

  28. Hi Dave,

    Try running a test on the new heater. You shouldn’t have any continuity to ground on the element. We’re happy to troubleshoot this with you in real time over the phone. Please call us when you’re ready.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  29. Like Tim on 10/15/20, I have 120v from each leg of heater to ground, but 0v (15.2 ohms) between the two, which makes no sense to me regardless of relay condition.

    Like

  30. Hi,

    That’s an indication that your heater is good, but the circuit board isn’t sending voltage to the heater. Give us a call when you have a moment near the tub and we’ll be happy to troubleshoot with you.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  31. Brian, we have all of a sudden had multiple problems with our 2010 Marquis EHT. The light was tripping the GFCI, so we isolated it from the board. At the same time the heater couldnt keep temp at 101*. We tested the heater circuit as you mentioned in previous posts and verified that there is an open across the element. Ordered a new heating element easy enough.

    We also only get one heater leg at 120v to ground and the other at 0v. Across both leads is also 0v. Sounds like a bad board/relay from what ive read above.

    Whats bothering us is that all these things happened at the same time. Coincidence or signs of a bigger problem?

    Would a bad heater element, i.e., shorted, cause the relay problem as well? Were gonna pull the board next and look for burns or discoloration. Thanks for sharing all the knowledge through these posts. Jay

    Like

  32. Hi Jay,
    It does sound like something catastrophic happened to the circuit board. It’s likely you’ll need to replace that to get the tub back up and running. If you run into any troubleshooting questions, give me a call at 800-823-3638 and we can go over them.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  33. No heat condition -Balboa BP 501. I am getting nearly zero volts across the two heater terminals but getting 110 on each of the legs. I’m guessing board issue?

    Like

  34. Hi John,

    You’re correct. If there are no topside error codes, the tub is calling for heat and you’re getting no voltage across the two heater element leads, the circuit board is bad, and should be replaced. If you can send us (help@spadepot.com) a photo of your current circuit board, we’ll be happy to let you know which replacement board you need.

    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  35. my temp would not stay down when I lowered it…..eventually the breaker tripped and will not reset….is it the thermostat or the element?

    Like

  36. Hi Rex,
    It sounds like you may have had a stuck relay, which would have sent voltage continuously to the element despite any attempt to turn the temperature down. Situations like this can be tricky, so give us a call when you have a moment to troubleshoot near the tub. We’ll walk you through what’s happening and how to fix it.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  37. Hello Brian,

    Have been working on a Master Spa Twilight with Balboa 4 kw 15 inch heating element. The 50A GFCI breaker was tripping. I unplugged the heater element and it quit tripping the 50A breaker, also noted corrosion on one of the connections points that I thought was the heater element failure. I installed a new heater element assembly and the GFCI quit tripping. The Spa temp rose from 50°F ish to the set temp of 102°F. I went out the next morning to ensure the spa was still running only to find the GFCI breaker had tripped again. Once again I unplugged the heater element and the breaker held. The heater element has 17k Ohms across it so the element appears to be ok. Any suggestions?

    Like

  38. Hi Cody,
    While the element may have the correct resistance, it could still be shorting to ground. Test for continuity from one of the heater element terminals to ground. If you have continuity, the element is indeed bad.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  39. Water Not heating up.

    Balboa PVS500Z
    Set to 120v
    4kw 800 15in 2×2 M7 stud
    On Power on: 61 43 12 Pr

    No error codes after prime

    115.7v measured across element poles while running

    Measured 16 ohms after taken off connections

    Pulled off and looked inside for sediment: spotless clean

    Reattached, opened valves, primed, retook measurements (only change was voltage went to 114.9v)

    Any hints on next steps?

    Like

  40. Hi Raul,
    It sounds like the heater is working, especially if you’re not getting any error codes. If this a new to you spa, it’s important to note that the heater @120v will only heat the water 1° (or less) per hour. Let it run for, say, 24 hours and check the temperature again. If you find the water hasn’t heated, give our technical department a call and we can dig a bit deeper.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  41. Hello, maybe you can help me and suggest troubleshooting ideas

    I have 2009 Dynasty Excalibur spa (2 pumps) with in.xe-5 spa pack . Few days ago I got error code FLO and missing temperature indication ( – – -). But pumps working well.
    I already replaced heater tube with build-in HL and FLO sensors but it does not help. All another indication on display works well. I suspect spa pack at fault or some remote temperature sensor (if it installed).
    Any ideas for troubleshooting will be appreciated. Mike

    Like

  42. Hi Mike,
    If pump 1 (pump flowing through the heater) is running at low speed and you’re getting that error code, it’s likely the pressure switch needs calibration. We’re happy to walk you through that, all you need is an ohmmeter. Give us a call when you have some time near the tub and we’ll be happy to help.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

  43. Replaced heater..titanium inside
    Top side shows temp reading of 107+
    (Cold water) in system.
    No lights in back of heater (amber or red).
    Can adjust press switch screw to get flc and back again to a number.

    Like

  44. Hi,
    What we really need to know is if the pump is moving water through the heater. Give us a call when you have a moment near the tub and we’ll be happy to troubleshoot the issue in real-time.
    Thanks,
    Brian
    SpaDepot.com
    800-823-3638

    Like

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