A tripped breaker, loose wire connection, faulty light, faulty switch or damaged cable are all reasons why a ceiling fan would work but not the lights. This post aims to cover these 4 reasons from the perspective of an electrician so you can fix the problem as soon as possible.
Firstly let’s look at how ceiling fans and lighting are typically wired.
Ceiling Fan & Lighting Fault Finding
The lighting and ceiling fan can either be on the same circuit or on two separate circuits depending on the layout of the home.
If they are on the same circuit, they will be controlled by the same circuit breaker in the switchboard. This means that both the fan and light can be shut off from a single miniature circuit breaker (MCB) and residual current device (RCD).
If the fan and light are a different circuits, then they will have their own circuit breakers at the switchboard.
Whether your ceiling fan and lighting are on separate circuits will depend on how your home is wired but in our experience if you are having problems with a ceiling fan and light located in the same room then they are most likely on the same circuit.
General Wiring
Modern ceiling fans are quiet and efficient drawing much less electrical current than their louder predecessors.
Fans can be wired with smaller 1mm2 or 1.5mm2 cable – this is the same sized cable used for modern LED lighting.
This cable will contain three wires – phase, neutral and earth. For the fan, this cable will go from the fan to a switch then from the switch to a circuit breaker in the switchboard. For the lighting, the cable will go from a light to the light switch and finally to the switchboard.
Ceiling Fan Working But Not The Lights? – Reason #1
Tripped Circuit Breaker
Likelihood: High Chance – If the ceiling fan is in a different room to the lights.
If the ceiling fan and faulty lights are located in different parts of the house then a tripped circuit breaker could be to blame.
The fan and lights would be on different circuits and therefore controlled by different circuit breakers at the switchboard.
Located in your switchboard, a circuit breaker automatically turns off power to a specific circuit when there is an electrical fault.
If a ceiling fan is working but not the lights it could simply be due to a tripped breaker shutting power to the lights.
A breaker will trip under three different circumstances namely short circuits, overloads and earth leakage faults (electric shock).
A MCB circuit breaker will shut off power in the event of a short circuit or overload.
A short circuit and overload can each cause a fire and an MCB is designed to shut off power before this happens.
An RCD circuit breaker will shut off power if there is any earth leakage. This means that an electric shock or risk of electric shock is occurring.
In either case if there is a tripped breaker there will be a good reason for it which should not be taken lightly.
Ceiling Fan Working But Not The Lights? – Reason #2
Faulty Light Fitting
Likelihood: High
A faulty light is a common occurrence. It can occur with any type of light including LED, fluorescent, halogen and more.
When a light becomes faulty it can also trip a circuit breaker because a short circuit is created.
A faulty light might have visible defects such as evidence of melting or discoloration where the short circuit occurred. There might even be weird smells.
Ceiling Fan Working But Not The Lights? – Reason #3
Faulty Light Switch
Likelihood: High
A faulty light switch is the next reason. Over time switches can feel soft to press which is a sign that the mechanism inside the switch has failed.
A switch can also show signs of melting and discoloration, especially if a dimmer is present. A faulty switch can also trip a breaker if contact between the phase wire and neutral occurs.
Ceiling Fan Working But Not The Lights? – Reason #4
Broken Or Loose Connection
Likelihood: Moderate
A broken or loose wire at the light, light switch or circuit breaker could also be the cause.
The phase or neutral wire becoming broken or loose is the most likely reason. An electrician would start at the light fitting and check the wires are connected properly. They would check the light switch and circuit breaker for any loose wires. They would ensure that the power is turned off at the switchboard before doing so.
Electricians Perspective
In our experience, a faulty light or faulty switch mechanism are the most likely reasons for why this is happening.
First check the light switch. If the switch feels too ‘easy’ or doesn’t have a click then that is probably the cause of the problem.
Replacing the light switch or mechanism should resolve the problem.
If there are no problems with the switch, the problem might be with the fitting itself.
Replacing the light fitting (or bulb) would be a good starting point.
We Fix Faults is a blog dedicated to finding out why electrical faults happen. If you’d like us to cover a topic send us a message above.