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HiringGarbage Disposals

Should I hire a plumber to install a garbage disposal?

Not always. A handy homeowner can swap a plug-in disposal for a similar one on the same drain. Hire a licensed plumber for a first-time install, a drain that has to be re-piped, a dishwasher hookup or a leak you cannot stop, and a licensed electrician for new wiring or an outlet, unless the plumber's licence covers it as incidental work. Anyone you pay must hold a Virginia licence.

Free to ask. Local shops send quotes, and you pay only when you book one.

By Kasra Taheri, Founder, LoclisPublished

Researched and drafted with AI, then checked claim by claim against the sources listed below before it was published. Prices and rules change; the dates beside each source say when it was last checked.

Step by step

Read when to stop and call a pro, further down this page, before you start.

  1. Step 1: Look under the sink

    Check whether there is a disposal there now, and whether its cord plugs into an outlet or a cable runs straight into the unit.

  2. Step 2: Check the drain

    Note whether the drain pipe in the wall sits below the disposal's outlet and whether the trap and pipes look sound or corroded.

  3. Step 3: Check the warranty

    If the old unit is failing within its warranty, call the maker first, because warranty service comes from its authorized service representatives.[3]

  4. Step 4: Decide the scope

    Do a plug-in swap yourself if everything lines up; hand anything involving new drain pipe, a new outlet or hardwiring to licensed trades.

  5. Step 5: Check the licence

    Look up the business on DPOR's licence lookup and confirm a plumbing licence, and ask who will do any wiring.[11]

  6. Step 6: Get it in writing

    Ask for a written contract that names the unit, the parts, the dishwasher hookup, any electrical work and the total price.[10]

You do not always need a plumber. A plug-in disposal swapped for a similar one, on the same mount, drain and outlet, is a job many homeowners do themselves in an afternoon. The cases for hiring are a first-time install, any change to the drain pipes, a dishwasher hookup you are unsure about, and leaks you cannot stop. New wiring or a new outlet is electrical work for a licensed electrician, unless it is incidental to the plumber's own licensed work. Whoever you pay has to be licensed in Virginia.

A black garbage disposal under a double kitchen sink, connected to white plastic drain pipes and a dishwasher hose and plugged into an outlet below
Photo: Tony Webster, CC BY 2.0, via Wikimedia Commons

When doing it yourself makes sense

Manufacturers design replacement disposals with homeowners in mind. InSinkErator calls installing one of its disposals a straightforward process for any handy person or plumber,[1] and says it designed its Standard Series for easy, do-it-yourself installation.[2]

A swap is a good DIY job when all of these are true:

  • There is a disposal there now, and it plugs into an outlet under the sink.
  • The new unit fits the old mount, or you are comfortable fitting a new sink flange in fresh putty.
  • The drain lines up and the trap and pipes are sound.
  • You can lift the unit overhead and lie under the sink for a while.

If that is your situation, the guide to replacing a garbage disposal walks through the job.

When to hire a plumber

A first-time install. With no disposal there now, the job is bigger. InSinkErator's first-install steps start by removing the existing P-trap, the horizontal extension pipe and the sink's strainer,[5] and then the drain has to be rebuilt around the disposal. That is plumbing, not an appliance swap.

A drain that does not line up. InSinkErator says the drain line should slope at least 1/4 inch per foot from the disposal to the drain connection, with that connection lower than the disposal's outlet.[3] If the drain in the wall is too high, or the old pipes are corroded, the fix is new drain piping.

A dishwasher connection. Once the drain plug is knocked out it cannot be put back, and if the dishwasher is connected without removing it, the dishwasher may overflow.[3] The dishwasher connection may run through an air gap,[5] and getting the hose routing right matters. If you are unsure, a plumber can check the routing.

Leaks you cannot stop. If the sink flange, mount or discharge tube still drips after you have reseated it, or water is damaging the cabinet floor, it is time to hand it over. The guide to fixing a leaking pipe under the sink covers the joints below the disposal.

A failure under warranty. Call the maker before anyone else. InSinkErator says "Only an authorized InSinkErator service representative may provide warranty service," and that the warranty is void if you attempt to repair the unit.[3]

When you need an electrician

Electrical work is a separate licensed trade. Bring in a licensed electrician, or confirm the plumber can do the wiring as work incidental to the plumbing job, when:

  • The disposal is hardwired. InSinkErator says a hardwired disposer needs a switch with a marked Off position installed within sight of the sink opening.[3]
  • There is no outlet in reach. If you add a cord to a new unit, InSinkErator's kit needs a three-wire grounded receptacle within 3 feet of the disposal, and the maker says, if the outlet is not properly located, to have one installed by a qualified electrician.[4]
  • The plug does not fit the outlet. InSinkErator says not to modify the plug or force it into the outlet, but to have a proper outlet installed by a qualified electrician.[3]

Some plumbing businesses hold both licences; ask when you request quotes.

What Virginia's licensing rules say

Virginia defines a tradesman as someone who works for the general public for compensation in the electrical, plumbing or HVAC trades,[6] and no individual may do that work without a tradesman licence, unless working under the supervision of a licensed tradesman in that specialty.[7] The same section says someone licensed in one specialty does not need a tradesman licence in another specialty "when performing work which is incidental to work being performed under their own specialty license."[7] Ask each plumber whether they will do the wiring under that rule or bring in a licensed electrician.

The Board for Contractors' regulations draw the same line for businesses. The plumbing contractor classification covers "the installation, maintenance, extension, alteration, or removal of all piping, fixtures, appliances, and appurtenances in connection with" sanitary drainage and the other systems it lists,[8] and the residential building contractor classification, which includes the functions carried out by home improvement contracting, "does not provide for electrical, plumbing, HVAC, or gas fitting services."[8]

Permits are a separate question from licences. Virginia's building code requires a permit for installations or alterations involving the sanitary drainage system or electric wiring, and it exempts the replacement of plumbing fixtures without alteration of the water supply, drainage or vent systems.[9] A plug-in swap leaves the pipes and wiring as they were; a first install, a new outlet or a re-routed drain does not. Ask whether the quote includes any permit and inspection your locality requires.

How to hire well

Describe the job precisely: whether there is a disposal now, how it is powered, whether a dishwasher drains through it, and which unit you want. Then:

  • Check the licence. Look up the business on DPOR's licence lookup.[11] DPOR warns: "A license number in an advertisement or on a business card does not necessarily mean the contractor's license is valid."[10]
  • Get it in writing. DPOR notes: "Virginia law requires all licensed contractors to provide a written contract for residential work."[10] The contract should name the unit, parts, any electrical work and the price.
  • Compare like with like. Ask each business to price the same unit and the same scope. There is more on prices in what garbage disposal installation costs in Virginia.

Stop and call a pro if

  • Wires run into the disposal with no plug, or the outlet under the sink is missing, damaged or the wrong type.
  • Water collects in the cabinet or the floor of the cabinet is soft or stained.
  • The drain backs up into the other sink bowl or the dishwasher after the install.
  • A breaker trips every time the disposal runs. Stop using it and have an electrician check the circuit.
  • You are on septic and unsure whether a disposal belongs on it. Read what you should never put down a garbage disposal first.

Getting help on Loclis

Loclis lists DPOR-licensed plumbing businesses with their licence number and class. Find plumbers in Blacksburg, browse garbage disposal services, or read more plumbing answers.

When you are ready, describe the disposal job once and licensed local plumbers quote it.

Common questions

Can a handyman install a garbage disposal in Virginia?
Only if they hold the right licence. Virginia requires a tradesman licence for plumbing and electrical work done for the public for compensation, unless the worker is supervised by a tradesman licensed in that specialty, and the residential building contractor classification, which includes the functions of home improvement contracting, does not cover plumbing or electrical services. Ask to see the licence and check it on DPOR's lookup.
Do I need an electrician as well as a plumber?
Only if there is electrical work. A plug-in disposal needs a grounded outlet within reach of its cord. If there is no outlet, the unit is hardwired, or a switch has to be added, that part is electrical work. It needs a licensed electrician unless the plumber is doing it as work incidental to the plumbing job, which Virginia's licensing law allows. Ask who will do it, and note that some plumbing businesses also hold an electrical licence.
Is a first-time disposal install harder than a replacement?
Usually, yes. The sink's strainer and part of the drain come out, the drain is rebuilt to suit the disposal, and there is often no outlet under the sink. That combination of drain work and power is why a first install is a good job to hire out.
My disposal is under warranty. Should I call a plumber?
Call the maker first. InSinkErator says only its authorized service representatives may provide warranty service, and that the warranty is void if you attempt to repair the unit yourself. Have the model, serial number and receipt ready.

Sources

  1. [1] FAQs: Garbage Disposal Support and Advice, InSinkErator. Checked October 26, 2026.
  2. [2] Garbage Disposal Installation (How-To), InSinkErator. Checked October 26, 2026.
  3. [3] Badger Series Installation, Care and Use Manual, InSinkErator. Checked October 26, 2026.
  4. [4] Power Supply Cord Assembly instruction sheet, InSinkErator. Checked October 26, 2026.
  5. [5] Installing a New Garbage Disposal, InSinkErator. Checked October 26, 2026.
  6. [6] § 54.1-1128. Definitions (tradesmen), Code of Virginia, Virginia General Assembly. Checked October 26, 2026.
  7. [7] § 54.1-1129. Necessity for licensure (tradesmen), Code of Virginia, Virginia General Assembly. Checked October 26, 2026.
  8. [8] 18VAC50-22-20. Definitions of license classifications, Virginia Administrative Code, Virginia General Assembly. Checked October 26, 2026.
  9. [9] 13VAC5-63-80. Section 108 Application for permit (Virginia Uniform Statewide Building Code), Virginia Administrative Code, Virginia General Assembly. Checked October 26, 2026.
  10. [10] What You Should Know Before You Hire a Contractor, Virginia Board for Contractors, DPOR. Checked October 26, 2026.
  11. [11] License Lookup, Virginia Department of Professional and Occupational Regulation. Checked October 26, 2026.

Want a pro to handle it?

Describe the job once. Licensed local businesses send quotes, and you pay only when you book one.