The licensing question comes before the price question
Minnesota's Department of Labor and Industry requires a plumbing contractor license for plumbing work in communities with more than 5,000 residents. Employees doing plumbing work must be licensed journeyworkers or master plumbers, registered unlicensed plumbers, or registered apprentices. Minnetonka is well above that size.
Connecting a disposal to a sink drain is plumbing, so a handyman working for pay needs to fit into that structure. Ask who is licensed, and check any name at the DLI Check a License lookup. A homeowner working on their own owner-occupied home is described differently on the city's permit form, covered below.
Doing the work badly is expensive in a different way. A loose slip nut under the sink drips for months into a cabinet floor, and a miswired unit is a shock and fire risk. Licensing exists so the person with the wrench has been trained and is accountable. Some cities do not require a permit for a like-for-like disposal swap, according to their own pages, but rules differ by town, so confirm locally.
Who does what: handyman, owner or plumber
The lines blur, so here is a practical split.
| Task | Handyman | Licensed plumber |
|---|---|---|
| Swap one disposal for the same model. | Often done, license questions apply. | Yes. |
| Add a disposal where none existed. | Needs plumbing, permit questions. | Yes. |
| Wire a new outlet or switch. | Electrician work. | Coordinates trades. |
| Change trap, drain or vent. | Plumbing work. | Yes. |
| Reconnect dishwasher drain. | Common, must be done right. | Yes. |
What a correct installation involves
Knowing these steps lets you check anyone's work.
Power off and prove it
Unplug the disposal or turn off its breaker and test the wires. If it is hardwired, do not touch the wires until the circuit is proven dead.
Remove the old unit and mounting ring
Disconnect the drain, support the disposal and release the mounting ring. Clean the sink flange and replace the plumber's putty or gasket.
Mount the new disposal
Seat the new flange, tighten the mounting assembly so the unit hangs level, and align the discharge with the trap. If a dishwasher connects here, knock out the plug inside the dishwasher inlet, or the dishwasher will not drain.
Connect the drain and power, then test
Attach the discharge tube and trap, connect the dishwasher drain hose with a high loop or air gap, then restore power. Run water for a minute and look for leaks at every gasket.
Choosing the unit before anyone arrives
A few choices at the store decide how smooth the install goes.
- Match the mounting system to your sink, or plan to replace the flange.
- Pick continuous feed for ease or batch feed if you want a lid-activated switch.
- Check cabinet depth, since large units hang low and crowd the trap.
- Confirm the dishwasher inlet and discharge positions fit your plumbing.
- Look for a power cord kit if your cabinet has an outlet and not a hardwired box.
- Keep the receipt and manual, because installers need the model details.
The step that ruins the first run
Many dishwasher hookups have a knockout plug inside the disposal's side inlet. If it is not removed, the dishwasher cannot drain, and water backs into the dishwasher. The fix is simple but awkward, and you must retrieve the plug from the disposal so it does not jam.
Another classic is leaving the wrong hose route. The dishwasher drain should loop up under the counter or through an air gap so sink water cannot siphon back into the dishwasher. If the old connection looked sloppy, ask for it to be corrected.
When the sink side needs a plumber's eye
A new disposal sits on top of old plumbing, and old plumbing shows its age under a dismantled sink. Corroded trap arms, a rusted drain tailpiece, leaking compression nuts and a double sink drain that is arranged oddly are all common. A good installer replaces what is worn.
If the sink drains slowly even before the new unit goes in, look at the line first. A clog downstream makes a new disposal back up too. For a unit that hums, jams or leaks, our garbage disposal repair visit comes first, and a fresh install makes sense only if the old one is spent.
Safety around the unit
Disposals do not have blades the way people picture them. They use spinning plates that fling waste against a grinding ring. Still, a hand in the chamber is a serious injury risk. Turn the power off at the breaker or unplug the unit first, and use a hex wrench in the bottom socket to free a jam.
Do not pour caustic drain cleaner into a disposal that clogs, since the liquid can splash back and corrode metal parts. Skip fibrous items such as celery, potato peels in bulk, and grease. Run cold water during grinding and for a short time afterward.
Reading a quote or a handyman's pitch
A solid quote names the unit, lists what is being replaced, says whether the dishwasher hose and trap are included, and says who pulls any needed permit. Vague line items such as 'misc plumbing' leave room for surprises. If the person cannot say who is licensed, the quote is incomplete.
Ask whether old parts are hauled away and whether the sink is tested with the dishwasher running. A short test cycle catches the knockout plug problem before the installer leaves.
What changes the cost of the job
Cost follows scope. A direct replacement with the same mounting system and a working outlet is simplest. Adding a disposal where none existed means new drain parts, an outlet or switch, and possibly a cabinet change. Higher horsepower units, batch-feed models and sound insulation cost more than basic ones, and a corroded trap adds parts.
For new fixtures and connections beyond a swap, a plumbing installation visit lets a plumber coordinate sink, dishwasher and drain pieces in one trip with a clear price before work starts.
What Minnetonka homeowners and renters should know about permits
The City of Minnetonka plumbing permit application says work is not to start without a permit and lists no exemptions. A residential owner applying for their own permit must own and occupy (homestead) the property. Ask the City of Minnetonka building department whether a disposal swap needs a permit, since the form does not say.
If you rent, you are not the owner-applicant. Ask your landlord or property manager who arranges the work, and do not hire anyone without that approval. A rental unit's share of the city's housing is something to ask the city about, not guess. Neighbors in Hopkins and Plymouth should check their own city rules.
Source: City of Minnetonka plumbing permit application.Questions about this topic
Not if there is already a working outlet or a hardwired box in the cabinet. New wiring or a new switch should be done by someone qualified for electrical work.
A like-for-like swap is often under two hours once the work area is clear. New wiring or drain changes take longer.
Horsepower matters less than quality of grinding and noise. A mid-range unit suits most households. Ask about batch feed or continuous feed.
With the power proven off it is safer, but use tongs or pliers to remove objects. Never reach in with the unit connected.
Only with the landlord's approval, and the permit form describes the owner-applicant as owner-occupier. Ask your landlord first.
Ask who holds the plumbing license, whether a permit will be pulled, and how the dishwasher connection will be done. Check the answer at the DLI lookup.
Related plumbing help
If this problem is happening now, these pages cover the work and the towns the 24/7 line serves.