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)

click here to find your new pool light

The Easy

Loose FixtureLOCK SCREW

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.

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 POOL LIGHT LENS GASKETthe 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.

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…

click here to find your new pool light

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.

TRIPPED BREAKERBefore 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.

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

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.

click here to find your new pool light

279 thoughts on “Tips for Troubleshooting Your Pool Light

  1. Hi! I have a 14 year-old Pentair 120V/100W incandescent, in-ground pool light that trips panel circuit breaker. 10K gallon salt pool. I am tempted to simply replace the fixture due to it’s age… without draining the pool, is it necessary to plug the niche conduit opening with pool putty/epoxy after fishing the new fixture cable through it?

    1. Epoxy can be used, but I suggest using a rubber cord stopper. These look like a rubber cork, that has been cored to allow the light cable through. These are easier to install and easier to remove in the future if you are changing the light again.

  2. My color wheel wasn’t working, so I took the pool light out. After finding out that the repair is going to cost more than I would like, I went to put the light back in; however, I had a small amount of water that I could see behind the pool lens. I replaced the gasket, but I consistently am noticing a small leak behind the pool lens. I have tried to screw the clamp and make the two sides touch…still leaks. I left about 1/2 inch of space between the two sides of clamp…still leaks. Any ideas as to how I can stop the leak so I can just put the light back into my pool?

  3. Hello Matt,

    My inground pool light comes on for somewhere between a few second and a minute then goes out. I wait awhile with the switch off then turn it back on and the same thing happens. I checked bulb wattage (100W) which is what the transformer is rated for. I checked J-box connections which are okay. Light fixture has no water in it and it is submerged. The only other things I can think of are a bad transformer or light fixture thermal protection. Your thoughts?

    1. Have you tested the voltage that is at the socket end? The wire connections could be good but a bad transformer is causing something to go wrong. Try a new bulb, just to eliminate that element.

  4. Hi Matt,
    I just purchased a brand new LED 35w light bulb to replace my old inground, burnt out halogen pool light bulb. I switched on the breaker and light switch, the light did not turn on. I can not reset the gcif, (the red and black button) is stuck and won’t “click” in. I’ve test the electricity in the outlet next to it, and it is working. Could I have a bad Gcif?

    1. It could be a bad GFCI, change it out and see if it fixes it.

      The only other thing I would check is if there is water in the light fixture. If water is in the fixture, that is causing the short.

  5. Is there a way to test the pool while the lights are on to make sure no one gets a shock while in the pool??

  6. Hi Matt, my bulb I just bought will not turn on, my buddy checked the fixture and it had 13 v running to it but the light would not fire in, the bulb is 12v new

    1. What kind of bulb is it? If it is an incandescent then shake the bulb, and listen for a loose filament. If it is a LED, it may be defective; depending on the manufacturer, they may have a way to troubleshooting the bulb.

  7. Installed an led light in a pentair housing. The bottom row got wet as water seeped in through the gasket. Only one day went by before I pulled the housing again. About 10 of the individual led’s no longer function. Will they come back after drying out, or are they gone for good?

    1. That is a wait and see game. You will have to give it time to dry out, and hopefully, the circuits can regain their pre-soaked integrity.

      If it works for an iPhone it may just work for a LED light.

  8. Just recently replaced my existing 120V bulbs with 120V LED’s and outside of the pool the lights worked perfectly. Once installed underwater in their sockets, they do not work. I assumed a leaky gasket and removed them back to the pool deck where they are bone dry internally. Powered back on and voila! Lights work……back underwater and nothing. Any clues as to what the culprit might be as I am befuddled and I am fairly experienced and familiar with electrical circuits.

    Thanks,

    Chris

    1. Are the breakers tripping when the bulbs are not working underwater?

      The hole in which the light fixture cable enters the light fixture, is it completely sealed? Does it seem irregularly loose?

  9. Hi

    I have a Hayward Colorlogic light in my pool that will not come on. What steps do I take to make sure it is the light and not something more?

  10. My pool light will go on and off by the remote, However it will not change color anymore. Any suggestions?

  11. Matthew…hoping you can help! My inground pool light has not been working for the last few years- there is water in the housing filling it about halfway which is likely what caused the bulb to fail. Sounds like a faulty gasket. From what I’ve read, this is an easy repair…but I’m worried about safety. If power is turned off at the breaker, can I safely unscrew and remove the fixture from the pool, open it, unscrew the bulb and replace it along with a new gasket and reinstall back in pool without fear of electrocution?

  12. Have a 120v Pentair LED Pool Light connected to a local J-box. This LED fixture was installed a few months ago to replace an incandescent fixture. Circuit runs through underground conduit approximately 60 ft., then up to a Photo Cell on the roof of a pool cabana, then back down to a GFCI Breaker in the main Breaker panel.
    Pool Light functions as it should at night, comes on at dusk and stays on all night. At dawn, when the Photo Cell triggers the light to turn off, the light goes into a cycle where it goes off for about 10 seconds, then comes on for about 10 seconds, then off, then on, and this cycle continues all day, even on a bright, sunshine-filled day, until dusk comes around and the photo cell triggers the circuit back on. Both the GFCI and the Photo Cell have been replaced recently, with no change. Baffled by the intermittent illumination during daylight…

      1. Could this be the type or style of Photo Cell…? potentially incompatible with LED lighting?
        Or a bad or missing heat sink in the pool light housing?

        My electrician seems to think we may have the neutral wire crossed with another neutral from some other circuit, though we have checked as much of the line as we can see or have access to…

  13. I’m stumped on why my GFCI keeps tripping. I have a spa and pool light. I replaced both lights with LED lights. Both worked perfectly. Then one day I flipped the breaker and the pool light dimmed and tripped the GFCI. I checked out the pool light and found water in the housing. Pulled the housing out and noticed water had only affected the light and not the socket. I replaced the GFCI but it keeps tripping with no bulb in the pool light. Got it to work for a few seconds with the spa light but it keeps tripping. Hoping I don’t have to pull a whole new pool light line.

      1. I have not tested the socket voltage yet. Don’t have a voltmeter. The spa light was installed in 2014. The first pool LED light was installed in 2016. I bought both of them on ebay. The spa light is a color changing LED bulb, I believe it is a J&J color splash. The pool light is a SMD bright white LED bulb. I know the bulbs are causing the problem. I think something may have shorted out the line, but not sure.

        1. So, the LED bulb got wet, you took it out and inspected it, then reinstalled it? After the install, the circuit still appears to trip? Well, the bulb may just be fried, or still wet on the inner components. Let the bulb dry for longer and then try it. Or get a standard incandescent bulb to test whether the breaker still trips?

  14. Matthew,

    Thanks a ton for all of this. I have a pool and spa light wired to the same 20 amp GFCI breaker in my pool panel. Sometimes the light will stay on as long as I want. Sometimes it will stay on for a few minutes. Most often it will stay on for 5-15 minutes then trip the breaker.

    I took off the panel and tested the leads going into the breaker. I got a 116.6 reading when the breaker was in the reset position. When I tested the same leads where they connect to the panel itself, I got the same reading. None of the other breakers in my panel for the filter, pump, etc. have ever tripped.

    Is my next step to test the power from the house that goes to the panel to make sure it is reading at least 120?

    Thanks

    1. Do you feel comfortable putting the light on a different breaker to determine if it is the breaker issue or if it is the light circuit? If the light does not trip on the new breaker, then the breaker may be the problem. If the new breaker does trip, then I would take a closer look at the light fixture. You can check the light housing for water on the bulb or cable issue.

      1. Thanks. I just bought a replacement breaker and will swap it out to see if that fixes it and report back. Thanks!

  15. Hi- We replaced a conventional pool light with a Hayward LPLUS11050 and it lasted for just over 2 years. Hayward sent us a replacement in January ’16 and it worked fine till last night. The light is flickering off and on again. We’re in South Florida so temp should not be an issue. These lights are advertised to last 10x longer than conventional and they should, given the price. Are they having quality issues with these lights?? I’m thinking I should be looking at a different manufacturer possibly. No issues with transformer or leaking….

    1. I have heard from several customers I the last couple years how the ColorLogic’s can be temperamental. For that reason, I usually try to guide people to the Pentair Intellbrite who has a lot better track record. I would give Hayward a call to get another warranty replacement.

  16. My pool light stop working a while back and we had someone come out and they said that the fixture was bad. Can you replace the fixture without having to pull a new wire? And how difficult is it to pull a new wire? My light is less that 25 feet from the power box.

  17. Hi Matt,

    I have 2 color splash bulbs, one in my pool and one I. Spa. Recently the pool is stuck on blue and only the spa will change colors or modes. Do you know what would be causing this? I turned off the breaker to reset the system and followed the reset directions with light switches.

  18. I have a question. I replaced the light and gasket in my pool light. It lasts about 1 – 2 days and then does not work. Any thoughts?

  19. im having trouble with the pool light, the pool light will automatically turn on its own and will start flickering both outside and inside the pannel (aqualink rs4)! i disconnected the landscape lights that were getting power from the power outlet of the pool where the junction box is, thinking it was out powered but still did the same thing! i replaced the whole light fixture and put in a Halco Pro LED bulb inside, what should i start checking?

  20. I have a kaleidoscope pool light. It turns on with no issues. However the kaleidoscope does not turn. I have flicked the on/off switch multiple times but no change in light color. There is a small reset button next to the switch but I believe it does not work. Your thoughts ?????

  21. Can ants in a junction box, along with some moisture cause a 12 volt spa light 100 watt bulb to blow? The multimeter measures a steady 12.8 volts, there is no water in the interior of the fixture however I do get 9 volts if I measure from the receptacle tip to the outside of the fixture housing……6 inch American Standard light fixture with 15 ft cord.

      1. Of course…the first new bulb lasted about four on/offs…..the second bulb worked once, then would not light upon the second turn on two days later….so my curiosity is wether ants disrupting this circuit could possibly cause a bulb to blow out or is this light done and need to be replaced for $150 or so? In other words…what issues would wet ants in the circuit box,wire nuts cause?

        1. Unfortunately, I am neither an exterminator or an electrician, so I couldn’t tell you with exact certainty what wet dead ants would do to a circuit. But if water got in there it could pop a bulb.

          If the voltage is sturdy, as you say, then there needs to be something else in the circuit (wet dead ants or otherwise) causing the bulbs to pop. Another possibility, though unlikely, is that you bought two defective bulbs in a row.

  22. My spa light will come on but my pool light won’t! I have changed out the bulb on the pool light but still nothing!

  23. I just replaced the bulb in my spa and it seems to work fine for a few minutes then as the water heats up it begins to intermittently go off and on, off and on. Purchased the bulb at a local Leslie’s . It is not tripping the breaker and the switch seems to work fine. Any ideas?

  24. A single GFCI connects the pool and spa light. Pool light works fine but when I turn the spa light, GFCI trips and obviously both the lights done work. I can reset and pool light works just fine.

    What troubleshooting steps should I follow?

    1. Does the spa light work fine with the pool light is not on? If the spa light works fine, then you may try changing the breaker. If the spa light trips the breaker even with the pool light off, your spa light cable or fixture may have a short. You will end to to pull the light to check if water is in the housing.

  25. Hi, I replaced my pentair remote and they did sync it but the spa light only comes on for 3 seconds the shuts off! Any suggestions?

Leave a Reply

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

Recommended Resources

Pool Pump Tripping Breaker?

Pool Pump Trips Breaker / GFCI

Electrical problems can be among the most mysterious and frustrating that pool owners experience.  They are also dangerous to the untrained...
Read Now

Do I need to drain my pool to replace my pool light?

March 16, 2018
Do I need to drain my pool to replace my pool light? In this video, we take a look at whether...
Watch Now

Looking for pool parts?

Shop Motors Shop Filters Shop Pumps Shop Salt Systems Shop Lights Shop Cleaners
Copyright © 2024 INYOpools All rights reserved