Dear Mr. Electrician: Is it easy to perform a kitchen hood replacement?
Answer: The work required to perform a kitchen hood replacement is determined by existing conditions and the new kitchen hood to be installed. NOTE: Some text links below go to applicable products on Amazon or EBay.
KITCHEN HOOD REPLACEMENT
The kitchen hoods that do not vent outside tend to be easier to install except for the chimney style.
Kitchen hoods that are vented outside require a little more work. If there is an existing exhaust duct for venting the hood outside, then duct fittings may need to be purchased or even fabricated at a sheet metal shop to fit the new hood in.
I saw the above kitchen hood exhaust vent on an old house that I was working on. You can see that it comes straight out of the back of the hood. The window glass was replaced with plastic.
The chimney style kitchen hood is a much longer and sometimes complicated installation process. There are more pieces to assemble and measurements are more precise.
One particular chimney hood that I installed took two men eight hours to complete. That was a hanging from the ceiling type with a glass hood with an attic above to work in and the roof vent already in place.
The wiring of chimney style hoods can be a little tricky. The electrical connections or electrical outlet are hidden behind the chimney. Read the installation instructions carefully to make sure you get every detail. I highly recommend downloading the installation instructions from the manufacturer’s website before purchasing a chimney style hood, or any hood for that matter.
Many of your existing standard kitchen hoods are hardwired in the back. However it is permissible to install an electrical outlet in the kitchen cabinet above and use a cord and plug to supply power to the new kitchen hood. You can see some examples of outlets that I installed in kitchen cabinets on my post about over-the-range microwave ovens.
I have posted photos below of the simple replacement of a kitchen hood.
The basic kitchen hood has a wiring compartment where the electrical connections are made. Usually one screw is all that is holding the cover to the wiring compartment in place.
With the wiring compartment cover removed you can see how power is brought into the back of the hood. A metal Romex connector prevents the cable from abrasion and movement. With the power turned off at the circuit breaker disconnect the wire connections and tape the bare ends of the wires with electrical tape temporarily while you work with them. Do not cut the wires.
Remove the locknut on the cable connector by turning it counter-clockwise. You may need to hammer it loose with a screwdriver. If the Romex connector is a plastic type, use diagonal pliers to cut it away in pieces. Do not cut the wires.
The original hood installer had to relocate the Romex cable to the other side where the power feed was located on the old hood. This is not unusual to find. There is no standardization of the wiring of kitchen hoods.
The electrician who does the rough wiring has no idea what type of hood will be installed. Consequently a lot of slack is left in the cable in case it must be moved. One reason to install an electrical outlet in the cabinet above instead of hard wiring the hood.
I always tape the bare ends of wires that I am working on using electrical tape. Even though the circuit breaker is off, there still could be current flowing on the white neutral conductor. I could also use wire connectors, however the taped ends lets me pull the wires through the cable connector and knock out.
A hole should have been drilled in the wall stud for this cable to go through instead of going on top of the stud.
This new kitchen hood has its wiring connections on the right side. I removed the electrical knockout in the back of the new hood and held it up to the wall and marked the location of the knockout on the wall. I pulled the cable back to where it was originally located and cut a small hole in the drywall for the cable connector to fit into using my keyhole saw.
I did a rough coat of joint compound and mesh tape over the groove in the wall before putting the new hood up.
I always keep boxes of screws and washers on my truck and I usually need them when installing a kitchen hood. Installation screws that are supplied by the manufacturer tend to be too short or not enough. I think #8 x 1.5″ sheet metal screws are best for the back wall going into a wall stud or the upper cabinet back. Shorter screws are good for screwing into the sides of the cabinets.
Many kitchen hoods come with slots for the mounting screws. You are supposed to install the screws ahead of time and then just hook and slide the hood over the screw heads.
I have used this method to install kitchen hoods, but only on flat bottom kitchen cabinets. Not all kitchen cabinets are flat bottom. Many have a recessed bottom. It is a little bit more difficult to align screws on a recessed bottom.
Sometimes I drilled one or two holes in the kitchen hood so that I can catch a wall stud with my screws.
Very simple wiring connections. The bare ground wire goes under the green screw. The green screw must be tight.
Click here to see my post about installing a microwave oven over a stove instead of a hood.