Your pool light won't come on. Here are the safe checks to try first and the point where a pro takes over.

When a pool light won't turn on, check the switch or timer, the breaker, and the GFCI, in that order. Those are the only checks a homeowner should make. If the light is still dark after them, the problem is in the wiring or the fixture, and that's work for a licensed or qualified pro.

I'm Adam, owner and lead technician at Adam's Pool & Spa in Long Beach, and I'm a Pentair Expert Installer and Jandy Certified. A dark pool light is one of the most common pool repairs I see, and most owners can rule out the easy causes in a few minutes. This guide shows exactly where to stop.

Is the switch or timer actually on?

Start here, because it's the easiest fix. Check the wall switch, any mechanical timer, and any automation app or panel that controls the light.

On a mechanical timer, look at whether the on and off pins are where they should be. On an automation system, check that the light isn't on a schedule that's off at the moment. If someone changed the clock or a power outage reset it, the light may simply be scheduled for the wrong time.

Could a color changing light just be switching modes?

Yes, and it can look like a dead light for a moment. Pentair's IntelliBrite pool light installation and user's guide says those lights change modes when you turn the switch off and on a set number of times.

The same guide notes that no light shows during that switching process, and calls that normal. So if someone flipped the switch several times, the light may be mid-change. Turn it off, wait a short while, and switch it on once before you assume it's broken.

Has the breaker tripped?

Check the breaker for the pool light at your main panel or the subpanel by the equipment. A tripped breaker sits in the middle or off position instead of fully on.

Reset it once by switching it fully off, then on again. If it trips again, leave it off. A breaker that won't hold is telling you there's a fault on that circuit, and that's a call for a pro.

Has the GFCI tripped?

Look for a GFCI outlet or breaker on the lighting circuit and see if it has tripped. The CPSC recommends following the National Electrical Code for installing GFCIs on 120 volt underwater lighting circuits. Pentair's IntelliBrite guide also lists a GFCI on the lighting circuit for its line voltage lights.

Press reset once. If the light comes on and stays on, you're done. If the GFCI trips again, stop there, because it's reacting to current going somewhere it shouldn't.

While you're there, the CPSC also recommends testing GFCIs monthly with the test and reset buttons. That's a good habit for each GFCI around the pool.

When should you stop and call a pro?

Stop the moment the next step means touching the fixture, the wiring, or the junction box. Pentair's guide says its underwater lights must be installed by a licensed or certified electrician or a qualified pool serviceman, following the National Electrical Code.

It also warns that improper installation creates an electrical hazard that could result in death or serious injury. Call a pro, and keep everyone out of the water, if you notice any of these:

• The breaker or GFCI trips again after one reset.
• You see water or fog inside the light lens.
• The light flickers, dims, or turns on and off by itself.
• The fixture looks loose or has pulled away from the wall.
• Anyone feels a tingle or shock in or near the water.

If anyone ever feels a shock, get everyone out and shut off power at the breaker. The CPSC recommends knowing where each switch and breaker for your pool equipment and lights is, so you can shut them off in an emergency.

What happens when a technician checks the light?

A pro checks the circuit and the fixture with the power off and the proper tools. That covers testing the supply, inspecting the wiring and bonding, and deciding whether the fixture needs a repair or a replacement.

That's part of our residential pool repair service. If you want to know how repair pricing works before anyone shows up, our guide on how much pool repair costs explains it.

The questions Long Beach pool owners ask most when the pool light goes dark, answered plainly.

Want the pool light looked at safely?

A dark pool light is worth fixing carefully. At Adam's Pool & Spa, I'll find out whether it's the switch, the circuit, or the fixture, and tell you what it needs before any work starts. We work across Long Beach and nearby neighborhoods, and we're Jandy Certified and a Pentair Expert Installer. Schedule a visit and I'll take it from the breaker on.

Adam is the founder, owner, and lead technician of Adam's Pool & Spa, working on pools in Long Beach and nearby LA County for about fifteen years. He is Jandy Certified and a Pentair Expert Installer, and he built the business on education-first, anti-pressure service, including the "Pool School" session each new client gets.

Written by

Adam

Owner & Lead Technician, Adam's Pool & Spa

Adam is the founder, owner, and lead technician of Adam's Pool & Spa, serving Long Beach and surrounding LA County for about 15 years. He is Jandy Certified and a Pentair Expert Installer, and he built the business on education-first, anti-pressure service — including the Pool School session every new client gets.