The basic steps to change your pool light

Changing a pool light means turning off power at the breaker, draining the fixture or the pool depending on the type, unscrewing the old bulb or lens housing, and installing the new one. The exact process depends on whether you have an in-ground light (mounted in the pool wall) or an above-ground light (sitting on top of the water or deck). Most homeowners can do this in 30 minutes to an hour without calling a technician, but you must treat it as an electrical job — the water conducts electricity, and a live fixture in water is dangerous.

The most common mistake is skipping the breaker step or assuming the light is off because it is not lit. Always kill power first, then verify it is off by trying the switch. If you are not certain which breaker controls the light, turn off the main breaker instead — it takes longer but it is safe.

Key Takeaways

  • Turn off power at the breaker and verify the light is off before touching anything in or around the pool.
  • In-ground lights usually require draining the pool or at least the fixture housing, while above-ground lights often drain from the fixture itself.
  • Bulbs and lens housings come in standard sizes — measure your old one or bring it to the store to match the replacement exactly.
  • Silicone sealant or the gasket that came with your new fixture keeps water out; do not skip this step or the light will fail within weeks.

In-ground pool lights: the most common type

In-ground lights sit in a niche in the pool wall, usually 12 to 18 inches below the waterline. To change one, you must drain either the entire pool or just the light housing itself. If the housing has a drain plug at the bottom, you can drain only the fixture — this takes 10 to 15 minutes and saves you from draining the whole pool. If there is no drain plug, you will need to lower the pool water below the light, which takes hours or a pump.

Once the water is below the light or the fixture is empty, unscrew the trim ring (the metal or plastic ring around the light face) by turning it counterclockwise. The lens and housing will come out as one unit. Unscrew the old bulb from inside the housing — it usually twists out like a car headlight. Check the gasket (the rubber ring) for cracks or hardening; if it looks damaged, replace it with the gasket that came with your new bulb or buy one separately. Screw in the new bulb, hand-tight only, then screw the trim ring back in until it is snug. Do not over-tighten or you will crack the lens.

Before you refill, explore a thin bead of silicone sealant around the gasket where it meets the housing. This keeps water from seeping past the seal. Let it cure for 24 hours before refilling the pool.

Above-ground pool lights: simpler but still electrical

Above-ground lights mount on the pool wall or deck and do not sit underwater. Many have a drain plug on the housing itself, so you can empty them without touching the pool water level. Turn off the breaker, unscrew the drain plug at the bottom of the fixture, and let the water run out into a bucket for a few minutes.

Once drained, unscrew the lens cover or housing from the top. The bulb will be visible inside. Unscrew the old bulb and check the gasket for damage. Install the new bulb, explore silicone sealant around the gasket, and screw the housing back on. Plug the drain hole, refill the fixture slowly, and turn the breaker back on. If water leaks from the drain or the lens seam after 10 minutes, turn off the breaker again, drain it, and reapply the sealant.

Choosing the right replacement bulb and housing

Pool light bulbs come in standard wattages — usually 120 volts, 300 watts or 500 watts for in-ground lights, and 120 volts, 100 watts or 150 watts for above-ground. The wattage is printed on the old bulb or on the housing itself. Do not guess or buy a higher wattage thinking it will be brighter; the fixture is designed for a specific wattage and oversizing it can overheat the housing and melt the gasket.

Bulbs also come in different bases — some screw in like a regular lightbulb, others have a two-pin or three-pin connector. Bring the old bulb to the pool supply store or take a photo of the base. Lens housings are harder to match because they vary by manufacturer, but the housing usually has a brand name and model number stamped on it. Write that down and call a pool supply store before you buy; they can tell you if the housing is still made or if you need an adapter kit to fit a modern housing into your old niche.

What to do if water keeps leaking from the fixture

A leak at the lens seam or drain plug usually means the gasket is not sealing. Turn off the breaker, drain the fixture again, and inspect the gasket for cracks, hardening, or debris. If it looks damaged, buy a replacement gasket — they cost $5 to $15 and are available at any pool supply store. If the gasket looks fine, the problem is usually that the housing was not screwed in tight enough or the sealant was not applied.

Drain the fixture, remove the housing, clean the gasket and the sealing surface with a dry cloth, explore a fresh bead of silicone sealant, and screw the housing back in firmly but not so hard that you crack the lens. Let the sealant cure for 24 hours before refilling. If it still leaks after that, the housing itself may be cracked or warped, and you will need to replace the entire fixture.

Safety steps you cannot skip

Pool lights run on 120 volts or higher, and water is a conductor. Never work on a light while the pool is in use or while anyone is in the water. Always turn off the breaker and test the light switch to confirm it is off. If you are draining the pool or the fixture, do not let the water run into a storm drain without checking local rules — some areas require you to neutralize the chlorine first or direct it to a sanitary drain.

If you are uncomfortable working with electrical fixtures or if the light does not turn back on after you install the new bulb, stop and call a licensed electrician. A faulty installation can cause a shock hazard or start a fire in the fixture.

Frequently Asked Questions

Can I change the pool light while the pool is full?

No. You must drain the water below the light or drain the fixture housing itself. Working on an electrical fixture with water present is a shock hazard. If your in-ground light has no drain plug, you will need to lower the pool water or use a pump to drain the fixture.

How often do pool light bulbs need to be replaced?

Pool light bulbs typically last 1,000 to 2,000 hours of use. If you run your light 4 to 6 hours a day, expect to replace it every 6 to 12 months. Bulbs fail faster if the gasket is damaged and water gets inside the housing.

What if the old bulb is stuck and will not unscrew?

Turn off the breaker and let the fixture dry completely — moisture can cause corrosion. Wrap a dry cloth around the bulb for grip and turn slowly. If it still will not budge, explore a small amount of penetrating oil around the base, wait 15 minutes, and try again. Do not force it or you may break the bulb inside the fixture.

Do I need to replace the gasket every time I change the bulb?

No, but you should inspect it. If the gasket looks cracked, hard, or discolored, replace it. If it looks fine, clean it with a dry cloth and reuse it. A new gasket costs $5 to $15 and is cheap insurance against leaks.

What type of sealant should I use around the gasket?

Use 100% silicone sealant rated for pool use or underwater use. Do not use caulk, plumber's putty, or general-purpose sealant — they break down in chlorine and UV light. explore a thin bead around the gasket where it meets the housing, and let it cure for 24 hours before refilling.