Swimming Pool Blog
by Rob Cox, June 22, 2011
Swimming Pool Lighting: Care & Repair
Q: How many pool guys does it take to change a pool lightbulb?
A: None, because you can do it yourself!
With just simple hand tools, you can do your own underwater pool light repair. When you need pool light parts, we have them in stock!
POOL LIGHT CARE: Fortunately, swimming pool lights require very little in the way of maintenance or regular care. There are some best practice in using your pool lights, however:
- Submerge before lighting. The heat buildup inside of a pool lamp is so great that the lens will burst if the pool light is left on while water is not covering the lamp, to keep it cool.
- Keep submerged during winter. This prevents the lens gasket from drying out. Keep the water level above the top of the lens to avoid pressure from the pool surface ice sheet that forms during winter.
- Use Light only as needed. Saves energy and reduces time between bulb changes.
- Maintain the light cord junction box clean and in good repair.
POOL LIGHT REPAIR: You will usually need a phillips head screwdriver to remove the screw that should be at 12:00 on the face of the bezel, or light ring. This one screw will allow you to remove the pool lamp from the light niche. The installers leave enough light cord rolled up inside of the niche to allow you to bring the pool lamp up on deck for inspection or repair.
- Replace Pool Light Bulb. Probably the most common repair. After pulling the lamp out of the niche (described above), Remove the clamp band (or in some cases, there are many small nuts or screws to remove. Use care with old, soft brass screws. Spray lubricant first, and use the proper size screwdriver, so as not to strip the head or even break off the screw head.
Once the clamp or nuts or screws are removed, you will need to separate the lens/gasket from the lamp housing. Use a large flat head screwdriver, inserted betweent the gasket and the lamp housing. Pry the lens/gasket from the housing. If you don't have a new lens gasket, use care with the gasket. It is considered best practice to replace the pool light lens gasket at the same time as replacing a bulb, but if you need to, you can probably reuse the existing gasket.
After removing the lens, check the bulb to see if it is screwed all the way in. Use a small cloth for safety. If the bulb is broken, use a thicker cloth. Push the cloth down into the base, and unscrew the broken bulb. This part is easy - everyone knows how to screw in a light bulb, right? Make sure the bulb is tight, and then before reassembling, test the pool light - for only 1 second!
Reassemble the pool light lens, making sure that it sits fully into the rim of the housing, and the gasket is properly positioned. Replace the clamp band, or the screws/nuts. Use a star pattern on screws/nuts when reinstalling, and make equal torque to all of them. For clamps, tap the band as you tighten, once or twice, to make sure the clamp is fully clamped around both sides - housing and lens.
Hold the lamp under water for a minute to test for leaks. A few bubbles will pop up, but if you see a steady stream of air bubbles, then you have a bad seal, and the light will quickly fill up with water. If not, then you are ready to install the pool lamp back into the niche. At the 6 o'clock position on most lights is a tab, insert the light into the tab first, then line up the screw hole at 12 o'clock. This can be a feat, since you are laying under the diving board, shoulder deep in water. Wearing a mask or goggles can be a big help at this stage. Screw in the screw at 12:00, and you are done!
- Repair leaking pool light niches Could be the second most common repair? Inground concrete and vinyl pools use a light niche that resembles a sideways bucket with a small hole in the upper back for the light cord to run through. This threaded port on the light niche is connected to gray pvc conduit, usually 3/4" diameter. This conduit runs up towards the deck, then runs under the deck to a point where it can turn upwards and come up to a junction box, where your pool light cord meets the power wires from the breaker panel.
Over time, the conduit can begin to leak, due to shifting pool or ground, or freeze damage. The conduit cracks or becomes separated from the niche. If you open your pool every spring and your pool water level is at the top of the light - your pool is leaking water through the pool light conduit.
Fortunately, there is a remedy to a leaking pool light. In the old days, we would use a big handful of pool putty, about half a package, to build a cone around the point where the light cord exits. Another method is to use a silicone product, but this cannot be done underwater. If you use silicone, be careful not to shoot too much into the conduit, as it makes a future pool light replacement difficult. The modern method however, is to use a cord stopper. These small rubber corks with a hole in the middle and a slit down the side are easy to install and remove.
Light niches can leak in the shell as well, especially older, copper niches. Pinholes can develop in older light niches, which can be patched for a time with pool putty or a silicone product. You can use a dye tester to determine if a suspected hole is actually leaking.
- Pool Light Power Problems Before you go pulling the lamp out of the pool wall, you may want to have a qualified electrician check for proper voltage reaching the light. This is most easily tested at the Junction box, the place where the pool light cord joins the power wires. Located directly behind the light, off the deck, and raised above the ground. Remove the lid, and test with a multi-meter or light tester device for 110-130 volts, or 11-13 volts for low volatage states like Maryland. If you have good power here at the j-box, the problem is likely the bulb.
If you find the power at the j-box to be low or non-existent, you can have a qualified electrician test the other legs in the circuit, running from the j-box back to the breaker panel, possibly through an outlet or light switch. The problem lies where the power dies, as the old saying goes. Breakers and switches can go bad, especially in an outdoor environment.
Another common problem is a popped GFI outlet. Electrical outlets at the equipment pad or near the pool are often run off the pool light circuit. Check the TEST buttons on these outlets, and push the RESET button.
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