Replacing a Bathroom Fan, Light, and Heater
A bathroom fan may be exhaust only, or it may be an actual bathroom fan, light, heater, or any combination thereof. If you have only an exhaust, replacing it with a heating and lighting unit may make the time you spend in the room far more pleasurable. The job requires no special training or tools. Purchase a replacement unit that is the same size as the original.
Step 1 - Disconnect Power
In the main circuit box, shut off the breaker for the room where you are working. Simply turning off the light switch is not sufficient. If necessary, run an extension cord and hook up a lamp for lighting.
Step 2 - Remove the Old Bathroom Fan, Light, Heater Unit
Most bathroom fans will have 1 to 4 screws which hold them in place. When you remove the screws, either the unit will drop down from the ceiling, or a panel will open that allows access to other fasteners. When the unit is loose, you should be able to access the wiring. If more than 1 wiring circuit is already in use, note which sets of wires connect to the different features of the exhaust unit.
Step 3 - Address Any Wiring Issues
If you are upgrading from a plain exhaust, you might need to run additional wiring from the light switch. You will also have several choices about the switch system, including dimmer/speed controls and multiple on/off controls. If you are using a customized switch system, the main thing is to keep the lighting, fan, and heating circuits.
Step 4 - Install the New Bathroom Fan, Light, and Heater Unit
Begin by connecting the wiring with wire nuts. The unit should come with an easy-to-follow diagram. Do not accidentally cross circuits for the different components. In a best-case scenario, even the screw holes will line up. If yours do not, keep some small self-tapping screws on hand for creating instant trouble-free pilot holes. You could also use a drill bit for pilot holes, but self-tapping screws cost much less and are compatible with any screwdriver with the correct screw tip.
Step 5 - Test It Out
Turn everything on at full power and let the unit operate for a few minutes to test the load on the circuit. If the breaker trips immediately when you turn the unit on, you have a direct short in the wiring. Turn the breaker off and carefully check the wiring connections for exposed or crossed wires.