If your disposal is leaking, jammed or backing up into the sink, switch it off at the wall switch first and, if you can reach it, unplug it or turn off its breaker. Never put your hand inside, even when the unit is off. Stop running the dishwasher, because its drain usually ties into the disposal, and put a bowl or bucket under any leak. Our line is open 24/7, so call while the sink is quiet and we will walk through what to check.
Water standing in both sink basins means the problem is probably past the disposal, in the kitchen drain line. Leave the stopper out, do not pour in cleaners and call us.
Disposals are small machines doing hard work, and most problems are one of a few things. A foreign object has jammed the flywheel, the motor has tripped, a seal has failed or the drain behind the unit is clogged. Knowing which is the difference between a ten minute reset and a replacement.
Common disposal problems and what each one means
Humming but not spinning
A hum with no spin is a jam. A bone, fruit pit or piece of silverware wedged under the shredder plate stops the flywheel, and the motor draws power without moving. We free it with a hex key from below or clear it from above with tools, never by hand.
Completely silent
No hum and no sound means the unit has no power. It may have tripped its reset button, lost a connection or burned out its motor. We test the outlet and wiring before replacing anything.
Leaking from the bottom
Water coming out of the base, near the motor, usually means a cracked housing or failed internal seal. That unit is not repairable in a practical sense, and a new one is the right fix.
Leaking at the top or sides
A loose flange, worn sink mounting gasket, failed drain hose clamp or a bad dishwasher connection can all cause water at the top or sides. Many of these are repairs, not replacements.
Slow drain or backup after use
Food solids, starch and grease coat the pipe behind the disposal and slowly narrow it. The unit grinds fine, but the water cannot leave, so the sink fills up.
How we handle a disposal call
Make it safe
We confirm the unit is off and disconnected before we touch it. Then we check the dishwasher line and the supply valves under the sink.
Find the cause
We try the reset, turn the flywheel with a wrench, test the power and run water to see where the leak appears. This sorts a repair from a replacement quickly.
Repair, replace, then clear the line
We clear a jam, tighten or replace a seal, or install a new disposal. Then we run water and check the drain line. A new disposal on a clogged line fails to solve the problem, so we test that part too.
Kitchen line backups: the drain behind your disposal
Many disposal calls are really kitchen drain calls. The unit looks guilty because the water is rising next to it, but the clog sits further down. Grease and ground food cool and harden inside the pipe, and a single cable pass through the disposal throat does not always reach it.
If the backup returns in a week, the line needs more than a plunger. Our drain cleaning service clears the kitchen branch with the right cable and head, and we can camera the line when it keeps coming back.
Fats, oils and your sewer lateral
Millbrae's sewer rules and what goes down the sink
In Millbrae, the sewer lateral on your lot is yours to maintain. Municipal Code section 8.20.430 says the owner clears obstructions on the lateral and must do so right away when found or when the city gives notice. The city maintains only the portion between the cleanout and the main, and only when the cleanout is in the designated place.
That makes what you grind a long-term decision. Fat and starch that coat the kitchen line do not stay in the kitchen, they travel into the lateral and add to buildups there. A disposal is meant for small food scraps with plenty of cold water, not grease, bones or fibrous peels.
Chapter 8.20 also sets a local limit of 100 mg/L on oil and grease in wastewater sent to the city sewer. The number is written for the system as a whole, but the idea applies in a home kitchen too. Fats in the drain are a sewer problem for the street and an expense for the owner of the pipe.
Repair or replace the disposal
| Symptom | Likely cause | Repair or replace |
|---|---|---|
| Hum, no spin | Jammed flywheel | Usually repair, free the jam and reset |
| No power, no hum | Tripped reset, bad outlet or burned motor | Check power first, replace if the motor is dead |
| Leak from the base | Cracked housing or internal seal | Replace the unit |
| Leak at the sink flange | Worn gasket or loose mounting | Repair, reseat the flange |
| Leak from the dishwasher hose | Loose clamp or cracked hose | Repair the connection |
| Backup after use | Clog in the drain line | Clear the line, disposal is often fine |
DIY or what people try
- Reaching into the unit with a hand or a spoon handle
- Pouring drain cleaner into a disposal that is jammed
- Running hot water and grease down together to "flush" it
- Replacing the disposal when the line behind it is clogged
Professional approach
- Power off, free the flywheel from below with the proper wrench
- Clear the line mechanically and test the drain before testing the disposal
- Install a disposal sized to your household and wire or plug it in properly
- Reconnect the dishwasher drain with a high loop or an air gap
Installing a new disposal
A new disposal needs a proper mounting flange, a gasket that seals the sink, a correct drain connection and a safe power source. Most kitchens are wired for a plug-in or a hardwired unit, and if there is no power at the sink, an electrician or a plumber with the right license has to add it. Permits may apply to new wiring or plumbing changes, and the Millbrae Building Division handles plumbing permits.
Size matters less than people think. A basic unit handles a small household's scraps, while a larger, quieter model costs more and fits only if the cabinet has room for it. We tell you what fits under your sink before you buy, and we install units you have already purchased.
What affects disposal pricing
A repair, a replacement and a line clearing are different jobs with different costs.
Unit chosen
Horsepower, noise insulation and build quality change the unit price a lot.
Repair or replace
A jam reset is quick, while removing and mounting a new unit takes longer.
Wiring and outlet
No power at the sink means more work.
Drain line condition
A clogged or leaking line behind the unit adds a second job.
Timing
After-hours calls are priced differently than scheduled visits.
Call the 24/7 line for a clear price before work starts. If you bought the unit yourself, tell us so we can price the install alone.
Disposal dead tonight? Call now
Tell us what the unit does when you flip the switch, whether water is leaking and if the sink is backing up. We use that to pick the right tools for the first visit.
Related kitchen plumbing
A leaking disposal and a leaking faucet often share the same cabinet and the same set of supply and drain connections. Our faucet repair page covers the fixture above the sink, and new fixtures or a kitchen remodel fall under plumbing installation.
We serve Millbrae and the next-door city of Burlingame, and the service area page shows what else we cover. Night calls for leaks and backups are welcome, and so are planned installs during the day.
Garbage disposal questions
Yes. The line is open 24/7 for leaking disposals, jams that stop the kitchen sink and backups. Switch the unit off at the wall, stop the dishwasher and call. We do not promise an arrival time, but we will tell you how to keep the mess contained.
Switch it off and do not put your hand inside. A hum with no spin is a jam. Many units have a hex socket on the bottom for turning the flywheel with a wrench. If that does not free it, call us.
Leaks from the base usually mean the housing or an internal seal has failed. That is rarely fixable, so we recommend replacement. Leaks at the top, sides or hose are different and are often repairs, so we find the source first.
Not always. If water rises in both sides of the sink or comes back after grinding, the clog is probably in the drain line behind the unit. We clear the line and test it before deciding whether the disposal needs work.
Avoid grease, oil and coffee grounds. Fat hardens in the pipe and grounds pack into sludge. In Millbrae the sewer lateral on your lot is the owner's to maintain, so buildup in your line becomes your repair bill.
A direct replacement is simple. Permits may apply to new wiring or changes to plumbing, and the Millbrae Building Division handles plumbing permits. We tell you which case you have when we see the sink.
Yes, in most cases. We check that the model fits under your sink, that the mounting matches and that the drain and power connections work. If something is wrong with the unit, we tell you before we install it.
Sources and standards: The California Plumbing Code (based on the Uniform Plumbing Code). Millbrae Municipal Code section 8.20.430. The sewer code limit on oil and grease.