Published on

Light Switch Stopped Working? Troubleshooting a Faulty Wall Switch

A light switch that isn’t working is a constant nuisance, whether you’re a tenant, a landlord, or a property manager. In some cases, a light switch that has stopped working may also be a sign of a fire hazard. Therefore, it’s important to address this issue as soon as possible. Here are some pro tips for troubleshooting a light switch that is faulty from the experts at Bolt Electric, New York City’s blue-chip, hyper-local professional electricians.

What Should You Check First?

Circuit breaker, fixture, and receptacle

Sometimes, what appears to be a malfunctioning light switch is actually not a problem with the switch at all. There are three things you should check first before turning to the switch:

1. Circuit breaker: make sure the circuit breaker hasn’t tripped and cut power to the switch. If the breaker trips repeatedly when you use the same switch, it’s a sign there’s a problem with the wiring on that circuit, which should be evaluated and repaired by a licensed electrician. It might be faulty, or it might simply be overloaded, which can be remedied with an electrical panel upgrade.
2. Fixture: check that any light fixtures you’re attempting to turn on aren’t loose. Also, look for loose bulb sockets and burned out light bulbs.
3. Receptacle: if the fixture you wish to turn on is also plugged into a receptacle (AKA outlet), make sure the plug isn’t loose and the receptacle is operating properly.

If all three of these items are not the cause of your switch problems, it’s time to move on to the steps outlined below.

What Is the Cause of the Switch Failure?

Switch or wiring

Next, you want to determine if the switch itself is bad or if it’s actually the wiring to the switch that’s malfunctioning. Some signs that a switch is bad include a loose toggle or obvious broken parts on the outer part of the switch. For example, if you flip the switch upwards and it falls back down again, the switch is broken.

You may not know the switch is bad until you check the wiring, as per the steps below. If the switch isn’t clearly broken, and you go through the wiring evaluation as described here but the switch still doesn’t work, assume it’s bad.

What Do You Do if the Switch Is Bad?

Replace the entire switch

Whether you decide the switch is bad at the outset or determine this after checking all the wiring, it will need to be replaced. Switches are contained units with multiple components that cannot be replaced individually. So, you will need to put in a completely new switch. This isn’t uncommon, as light switches are subject to heavy use, especially in rental and commercial properties.

Remember: always turn off the power supplying any circuit you are working on before attempting repairs to avoid electric shock. You can do this by turning the breaker controlling that circuit to the “off” position. If you’re not comfortable replacing a switch on your own or don’t have the tools, we are happy to do the job for you.

What Do You Do if the Wiring Is Faulty?

Buzzing, heat, or sparking

If you have been hearing buzzing or seeing sparks when you turn on a toggle switch, you have bigger problems than a failing switch. Likewise, if a switch feels hot to the touch after it’s been on for a while, you’ll want to address the issue right away.

This is a sign of a dangerous wire issue related to the switch. We suggest you turn off power to the circuit using the appropriate breaker on your electrical panel, and call your electrician. You likely need some rewiring done to make the circuitsafe for use again.

Loose wire

One potentially easy fix for handy folks is if you have a loose wire immediately behind the switch. One sign that this might be the cause of your problems is lights that flicker frequently. Vibration over time, as well as frequent use, can cause the wiring to the switch to become loosely connected or completely disconnected.

Before removing the switch and checking for loose wires, always cut the power to the circuit using your circuit breaker. You will need needle-nose pliers and both flathead and Phillips head screwdrivers on hand, as well as possibly a small wire-cutting tool.

Then you can reconnect the wiring, trimming off any frayed bits and reinforcing loose connections by tightening the terminal screw until it’s completely secure. Turn the power back on, try the switch, and test to make sure that solved the problem

A malfunctioning circuit cable

You can use a circuit tester (multimeter) to see if a malfunctioning circuit cable is causing the switch in question to fail. You’re looking to see if the circuit providing current (power) to the switch is complete (continuity) or if there is a fault in the wiring somewhere, preventing the switch from receiving adequate power (a “short circuit”).

As with checking for loose wires, first turn off power to the switch using the circuit breaker on your electrical panel. If you’re not certain if the breaker has properly cut the power, you can use a non-contact voltage tester to ensure there is no power. Next, disassemble the switch.

Pro tip: if this is your first time doing this type of repair, take photos with your mobile phone as you go. This will help you to reassemble everything as it was before. It will also assist you if you need to make a run to the hardware store or explain a problem to your electrician.

Turn the meter to “continuity test” mode (may also read “resistance,” “ohms,” or “Ω”). Flip the switch to the “on” position. Touch one of the screws on the side of the switch with one of the tester’s probes. Use the other probe to touch the bare copper ground wire or the ground screw on the switch.

Finally, touch the other screw terminal on the switch with one probe, and contact the other ground wire or screw with the other probe. Repeat these tests with the switch also in the “off” position. If you get no reading on the multimeter, the switch is not getting power, likely due to the circuit wiring. Time to call the electrician.

Do you need help testing your switches to see if they need replacement or if you have wiring problems that need repair? Call Bolt Electric at 212-434-0098, or use our online form to schedule an appointment. Don’t let malfunctioning switches become a long-term aggravation or dangerous wiring pose a fire hazard for your property. Reach out today.