Home / Articles / Tips for Troubleshooting Your Pool Light

Tips for Troubleshooting Your Pool Light

A glimmering pool light will add dazzling high notes to your poolscape; but a dim or broken light can leave you in the dark as to how to fix it. When your light goes kaput it is time to roll up the shirt sleeves, pull out the test probes and go to work.

But where to start? That is a tough question, as a pool light can have a hundred or so feet of cable, circuit breakers, GFCIs, and junction boxes to contest with. I’ve learned to start with the easy and then work your way up to the hard. We will walk through some simple fixes and some not so simple.

So, sit back, relax and let us enlighten you. I swear that is the last pun in this blog…

What’s the bright idea? (I lied)

The Easy

Loose Fixture

A pool light, despite all its waterproofing and hundred or so volts of electricity, is held into the pool wall by one bolt called the lockscrew. The lockscrew is located at the 12 o’clock position on the light fixture face. If the fixture wobbles when touched or a strong ripple hits it then a loose screw is likely the cause.

Lockscrew

To fix the issue, dip into your pool with a phillips head screwdriver and tighten the screw. If the screw is stripped or lost, make sure you replace the screw and the gum o-ring.  The o-ring is important to prevent excess water leakage into the niche or housing.

Leaky Pool Light

For the close observing swimmer, you may notice water in the light fixture. Most of the time, this issue is not discovered until the bulb blows. As we all should know, water and light sockets do not mix.

A leaky pool light stems from a bad lens gasket. This part is also called the housing gasket. The heavy gauge rubber ring acts as a clamp seal that waterproofs the joint between the lens and light housing. Chlorine exposure or old age can deteriorate the rubber to warp so that it allows water to reach the light internals. A fixture filled with water can also cause a breaker to trip, so be mindful of that when troubleshooting. Replacing a pools light lens gasket is pretty simple and even the more novice pool owners can do the job.

POOL LIGHT LENS GASKET
Pool Light Lens Gasket

Another less likely cause of a pool light fixture leak is a power cord conduit seal leak. If the conduit seal degrades to that point, the light is likely dead and will require replacement.

Change the Bulb

If your pool light will not turn on and you suspect the bulb, the old shake test is simple enough for  any pool owner to do. The steps on the bulb shake test are simple: remove the light bulb from the fixture and shake it next to your ear. If you hear the ring-a-ting-ting of a broken filament then it’s time for a new bulb.

If the bulb was relatively new before it blew, I would not run out and replace it right away.  A test of the circuitry may be necessary to be certain the new bulb will not be ruined by a power surge or some other electrical issue.  Take a look at our guide on replacing a pool light bulb.

The Not So Easy…

Tripping the Breaker

The dreaded CLICK of a tripped breaker is an annoying and sometimes befuddling event. Annoying because most of the time the reason for the trip is a mystery, unless of course you just plugged in an appliance that overloaded a circuit.

Before we do anything, we want to reset the breaker and also restore the circuit to the point before the trip. To perform the latter, we will unplug any appliance that may have immediately caused the overload.

Next, we will reset the breaker at the box. When a breaker is tripped, it flips to an idle position and will not resume current flow until it is completely reset by hand. To reset the breaker, find the flipped breaker, push it to the complete off position and then flip on. If the switch is not completely reset, it will spring back to idle. If you correctly reset the breaker but it continues to flip to neutral, replacing the breaker may be necessary.

TRIPPED BREAKER
Tripped Breaker

Bad Breaker

The actual task of checking the breaker is not the difficulty, mainly because the task consists of touching a couple probes to terminals. The usual hurdle homeowners have to overcome is getting a multimeter to complete the task. Your run of the mill meter can be found at a local hardware store or borrowed from friendly neighbor.

To test a single pole 120 Volt breaker we will need to remove the front panel of the breaker box to access the terminals. Before removing the panel, make sure to mark the switch that handles the light’s load.

The multimeter will have two leads: one Red lead (positive) and one Black lead  (Negative or Ground.)The black lead is connected to COM port and the red to the mAVΩ port, the latter will be touched to the “hot” wire to measure volt load. Set the multimeter to read 120 Volt AC or higher so it can accurately read your breaker.  Touch the red lead to the single pole terminal and the black lead to the neutral base row. The neutral row is normally labeled, but if it is not look for terminal row with the white wires.

Tripping the GFCI

The ground fault circuit interrupter, better known as the GFCI is a safety device used on installations with a higher than normal risk of electric shock. Most homeowners are familiar with GFCIs from their bathroom electrical sockets. The socket GFCI are also used on construction sites where machinery cords could come into contact with water or sheared.

GFCI BREAKER
Gfci Breaker

The GFCI works by reading a circuit’s current for an irregularity that could be a symptom of a shock hazard. A GFCI circuit can be activated by a current change as low as 4 milliamps. Interrupter switches are an absolute necessity for safety at home or work, but that sensitivity can cause a nuisance, quite literally.  A phenomenon known as nuisance tripping occurs when a GFCI trips when it mistakenly reads a current change as a potential shock hazard.

Common triggers of nuisance trips are:

  • Circuits longer than 100 feet
  • Lighting circuits using fluorescent bulbs
  • Permanently installed electric motors, i.e. bathroom exhaust fans

If the above do not apply to your tripping circuit, it may be time to replace your GFCI. Like any electronic component, these interrupter switches have a lifespan and need to be tested monthly to determine their status.

Line Continuity

A pool light may have up to 200 feet of wire running from the power source to the fixture. Within that length of cable, there may be a fault in a junction, the line or the fixture. Checking line continuity is the process of finding the source of a fault in circuit. Again this task can be done with the handy dandy multimeter. We will be starting from a point in which we assume you have already checked the GFCI and breaker as mentioned earlier in this piece.

  • Set the multimeter to read for 120 or 12-volt range for proper readings.
  • Measure line voltage at junction box. A junction box is the point at which multiple electrical device cables can be joined to one main line. Not all applications utilize a junction so this step may not apply.  If the junction reads 0 then the mainline leading to box is malfunctioning. Have an electrician inspect and install a new main line from box to breaker.
  • Remove fixture from niche, then remove bulb from fixture, touch multimeter leads to fixture socket for reading. If the meter reads 0 from the socket, the fixture is dead and needs to be completely replaced.

As you can see the testing of a pool light is straightforward due to the simple nature of its design. One electrical circuit to the fixture allows for a relatively easy troubleshoot without hard labor. As with anything electrical, if you have any questions or reservations, ask a professional before fiddling with live wires. A working pool light is not worth risking electrocution.

author avatar
Matthew Simmons Technical Writer & Pool Product Expert
Swimming pool expert at InyoPools and host of Poolside Chat, brings over a decade of experience in the pool industry.

Related Videos

279 responses to “Tips for Troubleshooting Your Pool Light”

  1. Eric W Avatar

    Hello,
    I have a bit of a stumper. I have 3 lights : pool, spa, and a patio pedestal light. Each light works fine independently from my pentagram easy touch control. Pool light and spa light can both be on at same time. Pedestal and spa light can be on at same time. But selecting pedestal and pool light will immediately trip gfci outlet. Any ideas before I call out an electrician?

    1. Matthew Simmons Avatar

      My first suspicion is that the combination of the two lights is overloading the breaker. The three lights likely have varying loads they put on the breaker, but the combination of the pool light (likely the biggest strain) and the pedestal light is too much. If you feel comfortable in doing so, I suggest putting a bigger GFCI on the circuit.

      1. Adam Avatar

        Hi my pool lights are both new and my timer when I go to turn on the lights the gfci trips immediately I’ve done tons of testing found that the neutral wire is grounded on my panel incoming 4g neutral I asked around and was told that it is supposed to be grounded but my question is why does my gfci trip so I eliminated the gfci as I was told was only for the receptacles and the lights work and don’t trip any breakers I would like to install the gfci back but is it really necessary to do so and what could cause the gfci to trip I pulled amps and it is pulling half of what rated and I replaced with new gfci to ensure it wasn’t weak and same results

        1. Matthew Simmons Avatar

          GFCIs are for safety reasons, any electrical appliances that are exposed to elements (water) should be protected by a GFCI. Have you had a licensed electrician check out the problem?

  2. Kara Avatar

    I have a beachcomber hot tub with a broken underwater light down at foot level. It’s rusted through the fixture-can I replace the this myself?

    1. Matthew Simmons Avatar

      I am not familiar with that spa model, so I could not tell you if that specific one is serviceable. I suggest contacting Beachcomber for assistance at 866-568-0668

      1. Marcus Avatar

        Hey friend. So i bought home 4 months ago, spa light never wekd, i fugured bad bulb, but main pool lightalways worked, i had compamy replaster pool so im taling they had to remove light to do replastering. But everytime i turn on light my gfci near pool equipment trips but if i tirn light swotch off, gfci will work everything else just fine ?

        1. Matthew Simmons Avatar

          Maybe they messed with the bonding of the light causing an issue with the circuit. But that sounds like an electrician should be brought in to figure out the issue.

  3. Tony Avatar

    Replaced my pool light (entire fixture) with a new Pentair LED light. Power is definitely running to the light but it does not turn on. Is there anything I could be missing or should I chalk it up to a defective fixture and return it? Light is definitely the 120v, not the 12v. The old light worked fine for years until it started taking in water.

    1. Matthew Simmons Avatar

      To me, it sounds like a dead light. You can always try to call the manufacturer to check if they have any tips, but those calls usually end with them deeming it defective as well.

      1. Tony Avatar

        Thank you, I spoke with Pentair and they agree, defective light. Thank you.

        1. Matthew Simmons Avatar

          No problem, glad to help.

  4. Dan Avatar

    My pool light has gone dim. Still working but not providing the brightness it once did. I haven’t been able to check the lens yet to see if there is a leak.

    1. Matthew Simmons Avatar

      Check the light voltage as well, or it could just be an old bulb.

  5. Mark Avatar

    My pool light system has a mind of its own. It’s on a Thermocraft junction box and wireless remote, but does not respond to the remote, and goes on and of at random times. We’d like to be able to turn on the lights only when we want to use the pool, and leave them off the rest of the time.

    1. Matthew Simmons Avatar

      I’m not sure what that could be, maybe you have a faulty control box or remote.

  6. Jack Avatar

    My spa light will come on for a second then trip the gfci. The bulb does not burn out. Disconnected spa light at junction box and hooked it to another gfci circuit. Same result popped gfci. So problem is from junction to the light. Are there any common problems that would cause this?

    1. Matthew Simmons Avatar

      Is the light properly grounded? The GFCI is meant to protect from faulty circuits, if the light is not grounded, no matter what GFCI it is connected to, the breaker will trip.

  7.  Avatar

    My spa light will come on for a second and then trip the gfci.

  8. James Avatar

    Thanks for responding. The problem is fixed now. I had a friend come over that knows his way around a multimeter better than me, and we discovered that the transformer was not working. Swapped the transformer out for another one, and the lights came on as if by magic! So it turns out ‘operator error’ was a factor in my repair..

    1. Matthew Simmons Avatar

      Ok, glad you fixed it. And don’t worry, “user error” mistakes happen to us DIY-ers more often than we will ever admit. 🙂

  9. James Avatar

    Hi Matt,
    I’m in a similar situation as Andy. The pool light won’t go on. I moved into this house 3 months ago, and some of the pool lights worked. Then they stopped working, I noticed water in the bulbs. Bought 2 new LED multi colour bulbs, and had the pool guy install them. Flicked the switch, and they don’t go on. Used multimeter to check power coming out of transformer (11.7v), and at the end of the cable by the light. Doesnt seem like there is power at the end of the wire. I find it hard to believe that the cable is fouled in 3 months.. How can i find out what the problem is?

    1. Matthew Simmons Avatar

      Interesting issue, James. Did the LED lights ever come on? Did you test the lights before you installed them? Also, if you only replaced the bulbs and the fixture was waterlogged, it may be beyond repair.

    2. Bill Avatar

      My new 12v low voltage color led zodiac didn’t work when pool Co installed it needed it for july 4th so they put in temp 120v led that worked fine they said they ordered a new light 2p days later installed another new 12v light this one does not work either I’m trying and fighting with them to fix it. It seems that they dont want to any troubleshooting of what the problem secratary just says we don’t or never use the 12v light but thats what i paid for since my last pool we had the list had water in it troubleshooting the problem would be my first choice to find the problem the only difference in lights is one has a step down transformer not sure if eirei g was cage for new light that doesn’t work either now I haven’t heard from them, I even called the manufacturer zodiac/jandy because pool security sad not compatable with pool equipment not true my whole system is jandy they work with with all pool equipment I’m getting the run around. I WISH THEY WOULD JUST TROUBLESHOOT IT 2 lights in a row being bad yaw Right. I’m thinking they burned out first light and put temp 12v I. Then Put first light back in so they can talk me in to a 12v light that we don’t want?

      1. Bill correcting last sentence Avatar

        I mentioned the 120v led light we don’t and didnt want.

        1. Luis Avatar

          I got color light but stay only one color what can I do

          1. Matthew Simmons Avatar

            Is this a new installation? Or is this an old light just acting up? Also, what model light do you have?

      2. Matthew Simmons Avatar

        Bill, is there a chance that you just have a bad transformer? You say the first 12 volt light does not work, then they installed a 120 volt light that worked fine, and then they tried another 12v light that did not work. My first thoughts went to a bad 12v transformer that is messing up the step down in voltage from 120 to 12. If the pool company doesn’t want to troubleshoot the problem, get an electrician to look at it.

        1. Easyfixlools Avatar

          Hey man I got a question about a wiring up a transformer through an pentair EasyTouch panel 8. And I have a 120 to 12 external transformer that’s wired up to a 12v intellibrite led color spa light and pool light. Is there any way using to get them to turn on and off or change colors separately or would I need two transformers and or one 12v one 120 light and run them through seleprate circuits relays? Trying to get ScreenLogic controller automation to run them seperately

          1. Matthew Simmons Avatar

            This may be the first time I have gotten this question, usually, pool owners are trying to make sure everything is synced up. The two lights cannot be operated as induvial circuits if they are hooked to the same transformer. You would have to add a separate transformer to be able to operate them independently.

      3.  Avatar

        Sounds like bad wiring. Did they wire up to a 120 to 12v transformer or to gfi!? If the 120 was working then then they bypassed the transformer and went to put a new 12v in and do not know how to install them and or your transformer could be bad.

  10. Andy Avatar

    Hi, my pool and spa light will not come on. I have checked breaker I case it has tripped. All okay. I have now removed and replaced the 20 v breaker. Still nothing. I have now removed the pool light fiture and replaced with a new bulb. Still nothing. Can you offer any advice? Thanks Andy

    1. Matthew Simmons Avatar

      Andy, has the GFCI tripped and maybe you forgot to reset it?

      Does the housing show any signs of corrosion or have you checked line continuity? If the fixture is the problem you will likely just have to replace the whole fixture. If the light cable is fouled then a replacement fixture will be necessary; unless, the problem lies in a junction box or some other power source connection.

      1. danny Avatar

        hi,i have a question about my swimming pool lights, one time i change the light 12 v. clip type now working,after 30 sec. i checked again,the light does not work,burning inside,but the breaker not tripping then i replace again at the same type, again burning the light ,the i check power output 12.4v. i need your advise.thanks

        1. Matthew Simmons Avatar

          What model light do you own? Also when you say it is “burning” do you mean the light pops and causes the bulb to fail? Or does burn mean something else?

          1. danny Avatar

            light model sp0581s15,made in usa,screw type,e27 300w/12v,yes sir i mean light pops causes bulb is fail,thanks for the reply sir..

          2. Matthew Simmons Avatar

            Have you tried putting the light on a different breaker? Or have you tested the voltage on the fixture side, or only at the breaker?

          3. Norman Avatar

            Hi Guys
            Want replacment LED POOL LIGHTS go to kiwipool.co.nz or email kiwipool@gmail.com
            Also has an Induction Led Pool Light as well as a replacement retro fit for the FIBER OPTIC LIGHTS THAT HAVE FAILED. ALL LOW VOLTAGE.

          4.  Avatar

            If a pool hot tub lightbulb gets too hot will that trip your GFR ?

      2. Tommy Torres Avatar

        I noticed one day that there was the light went out and there was water inside the light bulb I thought it was the Transformer had the Transformer replaced and the light bulb replaced and it’s still not working the inside of the light bulb has a little bit of corrosion like if it looks rusted because of the water got into it do you think it’s the whole system the whole light system

        1. Matthew Simmons Avatar

          A quick way to figure out if the circuit is intact is to use a voltmeter light fixture socket. If the socket is not receiving power then we know the light cable is corrupted. A new light fixture is a likely solution.

          1. jim Avatar

            Mine has 62 volts in the socket and the switch does not change anything
            4Inch hayward spa light

          2. Matthew Simmons Avatar

            If your socket is only getting 62 volts, that would be the problem. Bulbs generally come in two types, 120 or 12. Your socket voltage is in no man’s land. Did you switch it to a different breaker? If you have, and the voltage stays the same then your cord is shot.

          3. Azy Avatar

            Hi Matthew

            I have a pool light with Scenes, which I can control from my living room. It is not turning on at all now. I have not come across any topic about this kind of light on the internet. Can u plz help.

            Thanks.

          4. Matthew Simmons Avatar

            I have not heard of Scenes, so I couldn’t tell you much about it. If scenes is a manufacturer of a home automation system, it may be best to see if they can troubleshoot it.

          5.  Avatar

            Can I just remove the fixture only with out pulling the long wire out. And jut reseal it

          6. Matthew Simmons Avatar

            Are you asking about replacing the light fixture or removing it from the niche to troubleshoot it?

        2. Ida Avatar

          Hi my pool is only 2 years old built I have 3 led light one in the spa and two in the pool. One of the light from the pool stop working I don’t know if it’s of shit I calle I don’t know if i should contact Hayward warranty

          1. Matthew Simmons Avatar

            There are two basic options: you can try (or hire someone) to do the troubleshooting mentioned in the article or you can contact Hayward to have them try to troubleshoot with you.

      3. Lydia Avatar

        If my spa Led and my two pool led are on a easy touch and on one button does that mean they share the same breaker… my pool lights were put in last year…..

        1. Matthew Simmons Avatar

          Going by the EasyTouch wiring diagrams, yes that should mean they are on the same AUX circuit.

      4. Will Avatar

        I have a problem with my pool light as well. I replaced the bulb about a month ago and it worked the first day. The next day we went for a swim and It tripped the breaker. I figured water was in it but i was wrong. Now today i tried it just for fun and it works perfectly. Any idea whemy this would happen? I’m afraid it will happen again when i want to use it. Thanks

        1. Matthew Simmons Avatar

          My first and most obvious question, did you do any of the troubleshooting mentioned in the guide?

      5.  Avatar

        What would cause one of lights not to sync with other two that are synced. Even when they’re set to stay one color the one light gets changing colors. Is the bulb itself malfunctioning? Thanks

        1. Matthew Simmons Avatar

          If you know the light model, you can track down a troubleshooting guide pdf through google. Or you can have an electrician come in and take a look at the wiring. But my first move would be to ID the light to get a troubleshooting guide; it is the cheapest route.

    2.  Avatar

      How do I fix the pool light?

    3. azolivas Avatar

      There is a delay when turning on my LED pool light which can range from minutes , hours and days. It’s as if if it struggles to turn on but when it does it works fine. At first I thought it was the bulb but when I noticed it would eventually turn on I figured it has to be something else. Sometimes when I turn it on it is extremely dim but then after minutes , hours and even days it gets to full brightness. If this doesn’t make sense I can send a video of the issue. Could this be an electrical component within the pool equipment box wearing out ?

      1. Matthew Simmons Avatar

        The light circuitry is likely the problem. Some part of the LED’s PCB is faulty, causing a capacitor to charge slower, delaying the current from reaching the LED array.

        I’d hire an electrician to inspect the light and the circuit if you do not feel comfortable doing so.

Leave a Reply

Your email address will not be published. Required fields are marked *