Having a pool in your backyard can be a relaxing experience. It can be even more enjoyable if your pool is well-lit and you can swim in the evenings. There's nothing like an improperly working light, however, to ruin your pool fun. Before you begin to worry and call in a technician, attempt to troubleshoot the problems on your own.
If your pool light will not turn on, check that you don't have a tripped circuit breaker or a blown fuse. Also, check the Ground Fault Circuit Interrupter (GFCI) outlet. If there is a popped-out red button on it, your pool light will not be able to receive power. Push the button back in, to put it in the ON position. If it, or any other breakers or fuse, trip again, call a technician. If nothing is tripped, but you don't think there is any power, use a test meter to check for electricity at the breaker, switches and the junction box. Generally, the junction box is found off the deck, near the light. It is a small box with conduit pipes running into the bottom. It is often under or behind the diving board.
Bulb Replacement and Corrosion
If you find that all your switches are turned on, and they have power, remove the light fixture from its spot in the pool and check the bulb to see if it is burned out. If you need to replace the bulb, purchase one specifically designed for pool lights. If the power and the bulb are not your problem, corrosive water may have eaten away at the lamp fixture. The cord or the connections may also have been damaged. If these are the problem, you must replace your entire lamp fixture. Call a technician for this.
Water in the Lens
You may discover that, though your light continues to burn, water is behind the lens. If you notice this, remove the fixture from its niche in the pool. Let the entire lamp dry out. Chances are, the water is getting in through a spot in the gasket. Replace that piece, which is generally a lot less expensive than buying a new lamp fixture, or even a new bulb. If water still gets in, it may be coming in through where the cord penetrates the sealed unit. Check if there is room for water to seep through. You may be able to seal the leak with a two-part pool putty.