When your range hood stops working properly and needs to be replaced, here is a step-by-step guide to help you get the job done.
Step 1 - Disconnect the Power
Most range hoods use a circuit other than the one that powers the range. They are generally on a 120-volt circuit breaker. Turn both the fan and light from the range hood on and have another person turn the circuits off and then on until you find the one that controls the fan and other hood components. Once located, turn the circuit breaker off. If you cannot locate it, you can cut the main power source to the house.
Step 2 - Clear Some Space
If it is possible, move the electric range. Gas ranges may be too heavy, but if you have an electric range, you can likely slide it out of the way a bit to allow for ease of working. Either way, look at the cord sets and locate any flexible gas lines. These should never be moved or disconnected except by a licensed professional. If you are unable to move your range, leave it in place.
Step 3 - Inspect the Hood and Remove Hardware
If there is a cabinet above the hood, take a look at it to see how it is installed. This should provide some information as to how it is secured, ducted, and powered. Remove all the light bulbs, covers, and filters, as oftentimes some of the fasteners holding the hood in place are behind these.
Step 4 - Locate and Identify Wiring
Once all the covers are removed, you should now have access to the hood's wiring. Label each wire using a number or some identification on masking tape.
Step 5 - Disconnect Wiring
Unscrew the wire nuts or other connection hardware and cut off any wires that are using crimped connectors as close to the connector as possible to leave the greatest amount of wire.
Step 6 - Remove Conduit Connector or Cable Connector
Take the lock nut off of the fitting that is securing the cable or conduit in place within the wiring compartment. If you cannot remove this fitting now, you may be able to later when the hood is not secured.
Step 7 - Remove Fasteners
Have another person support the hood while you remove all of the fasteners save two at opposite ends of the hood. Loosen these two screws so that they are still holding up the hood, but can easily be removed.
Step 8 - Support the Hood
With your helper still supporting the hood, remove the final two screws and pull the hood down. It will most likely be very light, but also very bulking so try to have an area set aside to place the hood once it is disconnected.
Step 9 - Disconnect from the Power Line
Access your connectors and fittings and remove the power line from the hood by loosening the screw on the connector from the hood. If the range hood is not to be replaced right away, install an approved terminal box where the wires can be caped with wire nuts. It will make it safe in the meantime.
Step 10 - Restore Power
Once your wires are safely terminated, restore power to the hood if it was part of another circuit breaker or you had to turn the main power source off.