Fan switch turns on light? In many homes, especially rentals, it’s common for a fan to be on the same circuit as a light. This would mean that the fan and light both turn on from the same switch.
However, if the fan switch turns off a light in a random part of the house that will probably be caused by a fault like incorrect wiring.
I’m going to discuss different reasons why a seemingly unrelated fan switch might turn off a light. Then I will talk about what you should do if you want the light and fan to be on different switches.
Why The Fan Is On The Same Circuit As the Light
Fan switch turns on light? This is because the fan and light are on the same circuit.
In recent times there is more awareness about dampness in the home and the health issues it causes.
This has resulted in legislation and ventilation standards that require fans to be installed in areas such as bathrooms and kitchens.
Sometimes installing fans can be difficult in areas like bathrooms.
From an electrician’s perspective, getting a power feed from the location where a fan is legally required to be, to the switch location can be impractical.
It can be simpler (and cheaper) to get a power feed from a nearby light fitting and have the light and fan turn on at the same time.
This meets the legal requirements for ventilation while at the same time not requiring too much invasive work.
When the fan switch turns on, the light turns on too and vice versa.
How To Put The Light And Fan On Their Own Separate Switches
To put the fan and light on their own separate switches, you will need to get a cable from the fan (or the light) to the switch.
Depending on the layout of your bathroom this can be difficult or easy. It can also be pretty or ugly, and expensive or cheap for that matter.
Some homes have no accessible wall or ceiling cavity to bring the wire through, this means that the only way to control the fan on a separate switch is to get the wire from the fan to the switch with surface casing.
Surface Casing
Overall, surface casing is by far the ugliest, but cheapest option. If the colour of the walls is a neutral white you might be able to get away with it not looking so bad. It should only take a few hours of the electrician’s time.
Fan Switch Turns On Light In Random Part Of House – Reason #1
Installer Incorrect Wiring
If the fan switch turns off a light in a random part of the house, this would most likely be caused by incorrect wiring on the electrician’s part. For example, the electrician got a feed mixed up. This is why you would notice the fan switch turns on light in a random part of the house.
The solution to the problem is likely behind the switch causing this to happen.
Behind this switch might be other issues potentially causing this problem like broken or loose wires.
Fan Switch Turns On Light In Random Part Of House – Reason #2
Broken Or Loose Wires
Broken or loose wires might be causing electrical contact between random circuits, such as the fan and light.
Broken and loose wires can be caused by too much (and too little) tightening of wires as discussed here.
Wires can also be damaged by rodents, sharp objects and incorrect fusing (due to overloaded circuits melting cables).
Fixing broken or loose wires involves checking the light switch terminations. Before doing this it is important to ensure the circuit is safe to work on. This is why we always recommend that you engage a registered and experienced electrician rather than do it yourself.
Conclusion
Fan switch turns on light? Often a fan and light are intentionally on the same switch. This can be because the homeowner wanted this, or it can be because getting a wire from the fan or light to the switch was too difficult or expensive.
If you want the fan and light to be on a separate switch you need to run a separate wire from the fan or light to an independent switch. Depending on the practicality of this, it might mean you have to run the wires in surface casing. This can be very ugly depending on the layout of your bathroom.
Lastly, if the fan switch turns on light in random parts of the house it is because of a fault. The most likely reason would be the installer wrongly connecting the circuit, although broken and loose wires could also be the reason.
Next Steps
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- If you’d like free information on how to save money with electrician fault finding check out this guide