How to Replace a Range Hood: Easy Step-by-Step Guide

You’ve probably noticed that your range hood is either too loud to hold a conversation, doesn’t pull smoke like it used to, or just looks dated next to your new cooktop. Learning how to replace a range hood is a solid weekend project, but it’s not as simple as swapping out a light fixture. Get it wrong, and you’re looking at a fire hazard, a code violation, or a hood that just doesn’t work.

As of 2026, the National Electrical Code requires kitchen exhaust circuits to be GFCI-protected, and most local building codes mandate a minimum clearance of 24 to 30 inches above an electric cooktop. That’s the kind of detail that separates a safe install from a dangerous one. Let’s walk through what you actually need to know before you pull out the screwdriver.

Quick Answer

Turn off the power at the breaker. Remove the old hood. Disconnect the wiring.

Remove the old ductwork. Install the new mounting bracket. Connect the new hood’s wires.

Attach the ductwork. Secure the hood. Test it.

That’s the high-level version. The real work is in the details, matching duct sizes, knowing your local electrical code, and handling the weight safely.

Why This Job Isn’t Just a Simple Swap

A range hood is a hardwired appliance connected to both your electrical system and your ventilation ductwork. It’s not a plug-in device you can swap in five minutes. The wires are live until you kill the breaker.

The ductwork carries grease-laden air that can ignite if the wrong materials are used. And the hood itself is heavy, some pro-style models weigh over 60 pounds.

The biggest risk people overlook is the electrical side. Standard range hoods are hardwired into a junction box, usually hidden behind the hood or inside the cabinet above. If you don’t know which wire is hot, neutral, and ground, or if you mix up the connections, you’re creating a short circuit at best and a fire risk at worst.

Then there’s the ductwork. Your old hood might have been connected with flexible aluminum duct that’s now full of grease buildup. The National Fire Protection Association (NFPA) recommends rigid metal duct for range hoods because it’s less likely to trap grease and more resistant to fire.

If you’re using flexible duct, you’re already behind the safety curve.

And let’s talk about the clearance. If your new hood sits lower than the manufacturer’s recommended height above the cooktop, you’re violating the installation manual, and possibly your local building code. For gas ranges, that clearance is typically 30 to 36 inches.

For electric, it’s usually 24 to 30 inches. Measure before you drill.

Can You Do This Yourself? — A Quick Self-Assessment

Not everyone should tackle this job. Here’s a simple checklist to see if you’re the right person for it.

If you answered “No” to the electrical question, stop. Call a licensed electrician. The cost of hiring one for the wiring portion is far less than the cost of a fire or an electrical shock.

If you answered “No” to the ductwork question, you can still do the job yourself, but you’ll need to budget extra time and materials for replacing the duct.

For those who are comfortable with basic wiring and have done a light fixture or two before, this is a manageable project. For everyone else, consider this: the wiring is the part that kills people. Not the hood.

Not the duct. The wiring.

What You Need to Know Before You Touch a Wire

Before you even open the box of your new hood, gather these items. Missing one can stop your project cold.

Tools and materials you’ll need:

• Voltage tester or non-contact voltage detector
• Screwdrivers (Phillips and flathead)
• Wire strippers
• Wire nuts (sized for the gauge of your wiring)
• Drill with bits and screwdriver bits
• Drywall anchors or toggle bolts (if not hitting studs)
• Foil tape (UL-listed for duct sealing)
• Rigid metal duct (if replacing old ductwork)
• Duct transition fitting (if size changes)
• Pencil, tape measure, level
• Safety glasses and work gloves

Electrical specifics:

Your range hood wiring will have three wires: black (hot), white (neutral), and bare copper or green (ground). The house wiring in the junction box should match. If the house wiring is aluminum, stop and call an electrician.

Aluminum wiring requires special connectors and anti-oxidant compound that most DIYers don’t have on hand.

The circuit should be a dedicated 15-amp or 20-amp line. If it’s shared with other appliances, you might trip the breaker when the hood is running at high speed. Check the breaker panel before you start.

Ductwork specifics:

Measure the diameter of your existing duct. Standard sizes are 6-inch round, 7-inch round, and 3-1/4 by 10-inch rectangular. Your new hood might have a different collar size.

If it does, you’ll need a transition fitting. Never use tape to bridge a size gap, that’s a leak and a fire risk.

If you’re going from a ducted to a ductless setup, or vice versa, the entire ductwork path changes. A ductless hood recirculates air through charcoal filters and back into the kitchen. A ducted hood vents outside.

Switching between them requires either removing the duct (for ductless) or adding a new vent path (for ducted). That’s a bigger job than a straight swap, and it’s worth reading up on how ductless range hoods work before you start.

Step-by-Step: How to Replace a Range Hood Safely

Let’s walk through the process. Follow these steps in order, and don’t skip any.

Step 1: Turn off the power

Go to your breaker panel. Find the breaker that controls the kitchen circuit. Flip it off.

Then, use your voltage tester to confirm the wires at the hood are dead. Touch the tester to each wire. If it lights up or beeps, the breaker is wrong.

Try again. Never trust the switch on the wall, it might not cut power to the junction box.

Step 2: Remove the old hood

Unscrew the mounting screws that hold the hood to the cabinet or wall. Most hoods have two or four screws. Then, disconnect the ductwork.

It might be held together with foil tape, screws, or a friction fit. If it’s screwed, remove the screws. If it’s taped, cut the tape.

Now, disconnect the wiring. Open the junction box cover. Unscrew the wire nuts.

Separate the wires. Pull the old hood free. Be careful, it’s greasy and heavy.

Step 3: Prepare the mounting area

Clean the area where the old hood sat. Wipe down the cabinet bottom or wall. Check for any signs of water damage or grease buildup.

If the drywall is soft, patch it before installing the new hood.

Step 4: Install the new mounting bracket

Your new hood came with a mounting bracket. Hold it up to the ceiling or cabinet bottom. Use a level to make sure it’s straight.

Mark the screw holes. Drill pilot holes, then secure the bracket with the included screws. If you’re hitting drywall without a stud, use toggle bolts.

Step 5: Run the electrical connection

If you’re reusing the existing junction box, great. If not, you’ll need to install a new one. Feed the house wiring through the new hood’s junction box.

Connect the wires: black to black, white to white, ground to ground. Use wire nuts. Tug on each connection to make sure it’s tight.

Close the junction box cover.

Step 6: Attach the ductwork

Slide the new hood’s duct collar over the existing duct. If the sizes don’t match, use a transition fitting. Secure the joint with foil tape.

Do not use screws, they catch grease and create fire hazards. Seal every joint. If you have a backdraft damper, make sure it’s installed and opens freely.

Step 7: Secure the hood

Lift the hood onto the mounting bracket. It should click or slide into place. Some hoods have a secondary locking screw.

Follow the manufacturer’s instructions. Tighten everything. Give the hood a gentle tug to confirm it’s secure.

Step 8: Test the hood

Turn the breaker back on. Test the fan on all speeds. Test the light.

Check for any unusual noises. If the hood vibrates or rattles, the mounting might be loose or the ductwork might be touching something. Fix it now.

Ducting: The Difference Between a Working Hood and a Fire Hazard

The ductwork is the most overlooked part of a range hood replacement. People focus on the shiny new hood and forget about the greasy, crusty pipe behind it. That’s a mistake.

Rigid metal duct is the only safe choice for range hoods. It’s smooth, so grease doesn’t collect as easily. It’s non-combustible, so it won’t catch fire if the grease inside ignites.

And it’s rigid, so it doesn’t sag or collapse over time.

Flexible aluminum duct is the enemy. It’s corrugated, which means grease collects in the ridges. It’s also more likely to develop leaks.

If you have flexible duct, replace it with rigid metal. The cost is minimal, maybe $20 for a 5-foot section, and the safety improvement is massive.

The duct path matters too. The shorter and straighter the run, the better. Every 90-degree elbow adds about 15 to 25 feet of effective duct length.

That means your hood’s fan has to work harder, and it will be louder. If your duct run is longer than 25 feet of equivalent length, you might need a hood with higher CFM or an inline booster fan.

The termination point is also critical. Your duct must vent outside, not into an attic or crawl space. The NFPA and most building codes require the exhaust to terminate at least three feet from any window, door, or air intake.

If your old hood vents into the attic, that’s a code violation and a fire hazard. Fix it.

If you’re going ductless, the rules are different. You don’t need the ductwork, but you do need charcoal filters. Those filters must be replaced every six to 12 months, depending on usage.

A ductless setup is easier to install, but it’s less effective at removing heat and humidity. It’s a compromise that works best for electric cooktops in smaller kitchens.

Electrical Work: What You Can (and Cannot) Do Legally

The electrical connection is where most DIYers get into trouble. Here’s the honest breakdown.

What you can do yourself: Turn off the breaker, remove the old hood, disconnect the wire nuts, and reconnect the new hood’s wiring in the same junction box. If you’re replacing like for like and the circuit is already up to code, that’s a straightforward swap. You can also install a new junction box in the same location if the old one is damaged.

What you cannot do: Run new electrical cable through walls or ceilings. That requires a permit in most jurisdictions. You also cannot add a new circuit to the breaker panel yourself unless you’re a licensed electrician.

And you cannot change the wiring from hardwired to plug-in without installing a proper receptacle box and GFCI protection.

The gray area is the junction box location. If your new hood’s wiring doesn’t reach the existing junction box, you can’t just splice in an extension cord. You need to move the junction box or install a new one closer to the hood.

That means cutting drywall, running new cable, and patching the ceiling. That’s professional territory.

If you’re unsure about any of this, hire an electrician for the wiring portion. It costs $150 to $300 for a service call, and it’s the cheapest insurance you’ll ever buy.

The Code Requirements That Actually Matter

Building codes are regional, but some rules apply almost everywhere. Here’s what you need to know for a safe, legal install.

Clearance above cooktop: Gas ranges require 30 to 36 inches of clearance. Electric ranges require 24 to 30 inches. Measure from the cooktop surface to the bottom of the hood.

If you install a hood too low, you risk heat damage and fire. Too high, and the hood won’t capture smoke effectively.

Duct termination: Your exhaust duct must terminate outside the building. Not in the attic. Not in the crawl space.

Not in a garage. The termination point must be at least three feet from any window, door, or mechanical air intake. These rules come from the International Residential Code and the NFPA.

Make-up air requirements: If your range hood moves more than 400 CFM, some local codes require a make-up air system. That’s a separate duct that brings fresh air into the house to replace the air being exhausted. Without it, your house can go into negative pressure, which backdrafts water heaters and furnaces.

Check your local code before buying a high-CFM hood.

GFCI protection: As of the 2023 NEC, all kitchen exhaust circuits must be GFCI-protected. If your old hood isn’t on a GFCI breaker or outlet, you might need to upgrade the breaker. That’s a simple swap at the panel, but it requires comfort working inside the breaker box.

Permits: Some municipalities require a permit for any electrical work, including replacing a hardwired appliance. Call your local building department. Ask if a permit is needed.

The fine for skipping it can be hundreds of dollars, and it can cause issues when you sell the house.

Common Mistakes That Cost You Time or Safety

These are the errors people make most often. Avoid them and your install will go smoothly.

Mistake 1: Using the wrong duct material. Flexible aluminum duct is the most common mistake. It’s cheap, easy to install, and a fire hazard. Replace it with rigid metal duct.

End of story.

Mistake 2: Forgetting to check the duct size. Your new hood might have a 6-inch collar. Your old duct might be 7-inch. Or rectangular.

You need a transition fitting. Trying to force a mismatch with tape creates a leak and reduces performance.

Mistake 3: Not using a voltage tester. You turn off the breaker. You think it’s dead. But the breaker is mislabeled or the circuit is shared.

A non-contact voltage tester costs $15. Test every wire before you touch it.

Mistake 4: Over-tightening the mounting screws. Range hoods are heavy. It’s tempting to crank down on the screws. But too much torque can strip the screw holes or crack the mounting bracket.

Snug is good. Crushing is bad.

Mistake 5: Skipping the backdraft damper. If your new hood doesn’t have a built-in damper, you need to install one in the duct. Without it, cold air and pests can enter through the vent. Some dampers are built into the hood.

Some are separate. Check your manual.

Mistake 6: Ignoring the weight. A pro-style hood can weigh 60 to 80 pounds. Trying to lift it alone is a recipe for a dropped hood and a broken counter. Get a helper.

Use a temporary support board. Your back will thank you.

When to Absolutely Call a Professional

Some situations are not DIY-friendly. Here’s when you should pick up the phone instead of the drill.

You need to move the vent location. Cutting a new hole in your roof or exterior wall is a job for a professional. It involves roofing, siding, flashing, and proper sealing. One leak can cause thousands in water damage.

Your house has aluminum wiring. Aluminum wiring requires special connectors and techniques. If you’re not trained in aluminum wiring, don’t touch it. Call an electrician.

The ductwork runs through an unconditioned attic. Attic ductwork must be insulated and sealed properly. If it’s not, you’ll get condensation, mold, and reduced performance. A professional HVAC contractor can handle this.

Your new hood requires a new circuit. If the existing circuit is shared with other appliances or is too small, you need a new breaker and new wire run from the panel. That’s a permit-level job.

You’re not comfortable with the electrical work. There’s no shame in admitting this. The cost of a professional is a fraction of the cost of a fire. If you’re nervous, hire someone.

What to Do With the Old Hood and Ductwork

Your old hood is mostly metal and plastic. It can be recycled in most areas. Check with your local scrap metal recycler.

They’ll take the metal components for free. The plastic parts might need to go to a landfill.

The ductwork is also recyclable if it’s rigid metal. Flexible aluminum duct is usually not accepted by recyclers. It goes in the trash.

If the old hood is still functional, consider donating it. Habitat for Humanity ReStore accepts used appliances in good condition. Some local building supply reuse centers do too.

Call ahead to confirm.

The old wiring should be disposed of properly. Cut the wire into short lengths and take it to an electronics recycler. Never throw electrical wire in the regular trash.

The copper inside is valuable and recyclable.

If you’re replacing the ductwork through the attic, be careful removing the old sections. Grease buildup inside the duct is flammable. Wear gloves and a mask.

Seal the old duct in a heavy-duty trash bag before disposal.

Frequently Asked Questions

How long does it take to replace a range hood?

A straight swap takes one to three hours. If you need to replace ductwork, add another hour. Running new electrical wiring can take half a day or more.

Plan for a full afternoon if it’s your first time.

Do I need a permit to replace my range hood?

It depends on your local code. Many jurisdictions require a permit for any hardwired appliance replacement. Call your building department and ask.

The fine for skipping a permit can exceed the cost of the project.

Can I install a ductless hood if my old one was ducted?

Yes, but you need to remove the ductwork and cap the vent opening. You also need to install charcoal filters in the new hood. The performance will be different.

Ductless systems remove odors but not heat or humidity.

What size duct do most range hoods use?

The most common sizes are 6-inch round and 7-inch round. Some hoods use a 3-1/4 by 10-inch rectangular collar. Check your new hood’s specifications before buying transition fittings.

Is it safe to use flexible duct for a range hood?

No. Flexible aluminum duct is a fire hazard because grease collects in the ridges. Use rigid metal duct only.

The NFPA and most building codes require it. It costs more, but it’s the only safe option.