How to Change a Pool Light Without Draining the Water (A Step-by-Step Guide)

A burnt-out pool light is frustrating. Your beautiful backyard pool suddenly looks dark and uninviting at night. But your frustration likely turned to dread at the thought of fixing it. The idea of mixing electricity and water sounds dangerous, and the alternative — draining the entire pool for one light bulb—seems incredibly expensive and wasteful.

Let's start with the good news: Yes, you can absolutely change your pool light without draining a single drop of water.

It’s possible because pool lights are smartly designed. The light itself is a sealed unit that sits in a recessed "niche" in the pool wall. It's connected to a long, waterproof power cord that's coiled up behind it, allowing you to pull the entire fixture out of the water and onto the pool deck to work on it safely.

For most homeowners, this is a manageable DIY job. It just requires patience and a strict commitment to safety. This guide will walk you through the entire process, step-by-step, to help you get that light working again with confidence.

Before You Begin: Essential Tools and Safety

This is the most important part of the entire process. Do not skip these steps. Working safely with any electrical component, especially one near water, is non-negotiable.

Safety First

You must ensure the fixture is completely disconnected from its power source. Simply flipping the light switch is not enough.

1. Turn off the power at the main circuit breaker that controls your pool equipment. This is usually in your home's main breaker panel or a sub-panel near the pool equipment. Understanding your pool's electrical bonding and grounding is key to safety.
2. Post a note on the breaker box (e.g., "Pool Maintenance in Progress - DO NOT TOUCH") to prevent anyone from helpfully turning it back on while you're working.
3. Confirm the power is off. Go back to the pool light switch and flip it. If you're 100% sure you hit the right breaker, the light (if it was just dim or flickering) won't turn on. For absolute certainty, use a non-contact voltage tester at the switch to confirm there is no live current.

Tools & Materials You’ll Need

Gathering everything first will make the job go smoothly.

• Phillips-head and flat-head screwdrivers (a long-handled one is helpful)
• Your replacement bulb OR a new all-in-one LED fixture
• A new lens gasket (o-ring). This is critical. Do not reuse your old gasket, as this is the #1 cause of leaks that will ruin your new bulb.
• A soft, clean towel
• Gasket lubricant (if recommended by the gasket manufacturer)

Pro-Tip: This entire job is much easier if your water is clear. Before you start, you need to be able to clearly see the light fixture and the pilot screw from the pool deck. Keeping your pool free of debris and algae with a reliable automatic cleaner makes essential maintenance tasks like this one far less of a hassle.

Many pool owners find that wheeled robotic cleaners get stuck on raised elements, such as ground lights or main drains, which stops the cleaning cycle. This is where an Aiper robotic pool cleaner is different. Its tracked design allows it to grip and climb over these obstacles smoothly, just like a tank, ensuring an uninterrupted clean and preventing it from getting stuck on the very fixture you're trying to fix. If you're not sure where to start, here's how to choose a swimming pool cleaner that's right for your needs.

How to Replace Your Pool Light: A Step-by-Step Walkthrough

With your power off and your tools ready, it's time to get started.

Step 1: Remove the Pilot Screw and Loosen the Fixture

Look at the light fixture. There is typically a single pilot screw holding it in place (though some older models may have two). This screw is most often at the 12 o'clock position, but it could be at the bottom.

Use your screwdriver to remove this screw. It can sometimes be difficult to loosen if it's been in place for years. Once the screw is out, the fixture is only held in the niche by friction or retaining tabs. Gently use your flat-head screwdriver to pry the fixture out of the niche.

Step 2: Bring the Light Fixture onto the Pool Deck

This is the "ah-ha!" moment. Slowly and gently begin to pull the light fixture away from the wall. You will feel the coiled power cord unspooling from behind it. There is usually several feet of extra cord, more than enough to lift the entire housing out of the water and set it on the towel you placed on your pool deck.

Step 3: Open the Light Housing and Replace the Bulb

With the housing on the deck, find the series of brass screws or the metal clamp that holds the lens and faceplate to the back of the housing.

• Carefully loosen and remove these screws.
• Separate the lens from the housing. The old gasket may make it stick a bit.
• Thoroughly dry any moisture inside the housing with your towel.
• Unscrew the old bulb and screw in the new one. (If you are replacing the entire fixture, you'll disconnect the old unit at its cord and follow the new manufacturer's instructions).

Step 4: Install the New Gasket and Re-Seal the Housing

This is the most crucial step for success. A bad seal will cause the light to fail again in a matter of weeks.

1. Remove the old, compressed gasket from the lens or housing.
2. Thoroughly clean the grooves on both the housing and the glass lens. All old gasket residue, grit, or mineral buildup must be removed.
3. Properly seat the new gasket in its groove. Make sure it isn't twisted or pinched.
4. Re-assemble the lens and housing. Tighten the clamps or screws in an alternating "star" pattern, just like changing a tire. This ensures the lens is seated evenly and the gasket compresses uniformly to create a perfect waterproof seal.

Step 5: Test the Seal (The "Bubble Test")

Before putting the light back in the wall, perform this simple test. With the fixture still on the deck, lower the newly-sealed unit into the water and hold it submerged for a minute. Watch it closely.

If you see a steady stream of air bubbles coming from the housing, your seal is bad. This indicates a leak, and you need to know how to find a pool leak to fix it. You must pull it out, open it, dry everything, and re-seat the gasket. A few trapped-air bubbles right at the start are normal, but a continuous stream is a sign of a bad seal.

Step 6: Coil the Cord and Secure the Fixture

Once you're confident the seal is watertight, carefully feed the power cord back into the niche as you guide the light fixture back into place. Wrap the cord around the back of the fixture as you go, which helps it all fit neatly.

Press the fixture back into the niche until it's flush. Line up the screw hole and re-install the single pilot screw to secure it.

Step 7: Turn On the Power and Test Your Work

Head back to the circuit breaker, remove your warning note, and flip the power back on. Go to your light switch and turn it on. If all went well, you'll have a bright, beautiful light shining in your pool.

Upgrading to LED? What You Need to Know

Since you're doing the work anyway, this is the perfect time to upgrade from an old, hot-running incandescent bulb to a modern LED. This is a key part of any eco-friendly pool maintenance plan.

• Benefits: LEDs are dramatically more energy-efficient, last thousands of hours longer, and are available in a variety of colors and remote-controlled color-changing options. For a full breakdown, see this pool lighting guide.
• Bulb vs. Fixture: You have two choices. You can buy an "LED replacement bulb" that's designed to fit inside your existing housing. Or, you can buy an entire new, fully-sealed LED fixture. The fully-sealed units are often more reliable as they eliminate the risk of you getting a bad gasket seal.

Common Problems and When to Call a Pro

It's an empowering DIY project, but it can have hangups. Here’s what to do if you get stuck.

What If My Light Fixture is Stuck?

If the fixture won't budge after you remove the screw, it's likely "stuck" from years of black algae or mineral buildup. You can try to gently pry around the edges with your flathead screwdriver. Do not use excessive force, as you don't want to crack the niche.

What if the Screw Is Rusted or Stripped?

This is a common and frustrating problem. A stripped screw may require a special screw extractor tool. A rusted-off screw head may mean you have to drill it out. This complicates the job significantly, and it may be a good time to call a professional.

Signs You Should Stop and Call an Electrician

Your safety and your pool's integrity are more important than finishing a DIY project. Stop immediately and call a pro if you notice:

• The power cord insulation is brittle, cracked, or frayed.
• The niche (the housing in the wall) is cracked or damaged.
• The water in the niche appears to be draining (this could mean a leak in the conduit).
• You are at all unsure or uncomfortable with the electrical work.

Deciding between DIY and a professional service is about knowing your limits. It's always better to pay a professional for an hour or two of work than to risk electrical shock or a major, costly leak.

Your Pool Light Questions Answered (FAQ)

How much does it cost to replace a pool light?

If you DIY, your only costs are the parts. A new LED replacement bulb and gasket kit can cost anywhere from $50 to $150. A full new LED fixture can range from $200 to $500+. This is one of many pool maintenance money-saving tips. Hiring a pool professional or electrician typically costs $100-$250 in labor, plus the cost of the parts.

Do I have to drain the pool to change the light?

No. As this guide shows, pool lights are designed to be serviced from the pool deck with the pool full. The long cord makes it possible to work on the light safely out of the water.

Why did my pool light burn out so fast?

The most common reason for a pool light to fail prematurely is not the bulb itself, but a faulty gasket seal. Even a tiny, slow leak allows moisture into the housing, which will quickly destroy the bulb and socket. This is why replacing the gasket every single time you open the fixture is so important. If you suspect a leak, you can do a bucket test to confirm.