How to Install a Double Sink With Garbage Disposal in Loma Linda, CA
A double kitchen sink with a disposal is a weekend project for some and a licensed job for others. Here is how the work goes and where Loma Linda homeowners should stop.
What the job involves from start to finish
To install a double sink with a garbage disposal, you set the sink in the counter, connect both bowls to one drain with a trap, and mount the disposal on one bowl. Then you link the dishwasher drain if you have one and wire the disposal to power. Each stage has its own risks, and the last one involves electricity close to water.
Most of the time spent is on the drain. Two bowls need a tailpiece each, a connecting pipe between them, and one trap that leads into the wall. The disposal replaces the strainer on one bowl, so its outlet must line up with the connecting pipe.
If your existing kitchen already has a single sink and a drain in the wall, the drain stub usually stays where it is. Moving it means opening the wall, and that is plumbing alteration, not a simple swap.
Parts and tools to gather first
| Part | What it does | Watch for |
|---|---|---|
| Double bowl sink and clips | Sits in the countertop cutout | Cutout size must match the sink template |
| Basket strainer for the bowl without the disposal | Seals the second drain | Use plumber's putty or the gasket supplied |
| Disposal with mounting ring | Grinds food waste below the first bowl | Choose one that fits the sink flange |
| Continuous waste or tee fitting | Joins the two drains | Both outlets must slope toward the trap |
| P-trap and trap arm | Holds the water seal | Trap arm must slope toward the wall stub |
| Dishwasher drain hose | Carries wash water to the disposal inlet | Needs a high loop or an air gap |
| Power cord kit or wiring | Powers the disposal | Match the unit and the circuit |
You will also need a basin wrench, channel-lock pliers, a screwdriver, a hacksaw or tubing cutter, a flashlight and a bucket. Read the disposal instructions first, because mounting rings differ by maker.
Step by step, in the order that avoids mistakes
- Turn off the water to the sink and shut off power to the circuit at the panel if there is any wiring or outlet under the sink.
- Remove the old sink and trap. Scrape the old sealant off the counter.
- Set the new sink on the counter, secure the clips from below, and run a bead of sealant around the rim.
- Install the strainer in the bowl without the disposal, and the disposal sink flange in the other bowl.
- Attach the mounting ring, hang the disposal on it and rotate to lock, following the maker's directions.
- Join the second bowl to the disposal outlet with the tee or continuous waste, then to the trap and the wall stub.
- If you have a dishwasher, remove the knockout plug inside the disposal inlet, a step many first-timers miss, and then connect the drain hose.
- Fill both bowls, check every joint for drips, and run water through the disposal before turning on the power.
Do not skip step seven. A dishwasher that will not drain after a new install is often a knockout plug that was never removed.
The dishwasher drain: high loop or air gap
The dishwasher drain hose should not sit lower than the water level in the sink drain. Most makers call for a high loop, in which the hose goes up under the countertop and is clipped there before dropping to the disposal. Some jobs use an air gap fitting on the sink deck instead. Follow the dishwasher manual, and ask a plumber if your layout does not match either picture.
This is not a fiddly detail. A hose that dips low can let dirty water flow back into the dishwasher, and the smell and the stains will tell you.
Electrical safety is the hard line
A disposal needs power, and a wet cabinet under a sink is exactly where an electrical mistake hurts. Turn off the breaker for the disposal circuit and test the wires with a tester made for the job before you touch them. If any part of the cabinet is wet, do not reach into it until the power is off, and if you cannot reach the panel without standing in water, stay out and call for help.
Hardwiring a disposal, adding a switch or running a new circuit is electrical work. A homeowner who is not comfortable with it should hire a licensed electrician or a plumber who works with an electrician. A cord and an outlet under the sink must be on a circuit that meets code, and that is not a guess you want to make alone.
Never put your hand into a disposal. Use tongs or pliers for a stuck item, with the power off at the breaker, and not only the wall switch.
Loma Linda local note: permits, rentals and licence rules
Loma Linda's Building and Safety Division states that plumbing work needs its own permit, separate from electrical and mechanical work, and that a licensed contractor or the owner must obtain it. The city pages do not name sink or disposal replacements, so permit rules vary. If your plan involves moving the drain or adding a circuit, call the division and ask before you start.
The state licence board says a contractor licence is required once the total cost of labor and materials for a project reaches its published threshold, and also for any job that needs a building permit or uses additional workers, regardless of cost. If you hire help, look up the contractor on the board's online lookup first. Licensed work is the rule, not the exception, for anything beyond a simple swap you do yourself.
About 62 percent of households in Loma Linda are renters, according to census survey figures. If you rent, you usually need the landlord's written approval before swapping the sink or adding a disposal. Put the request in writing and ask who will do the work and who pulls any permit.
When to do it yourself and when to call
A same-size sink swap with a new basket strainer and a disposal that plugs into an existing outlet is within reach for a careful homeowner. A new drain location, a new circuit, a gas range near the work, or any wall opening is where a licensed pro earns the job.
Hiring out the plumbing but doing the sink set yourself is a common middle path. Ask whether a plumber can handle just the drain and disposal connection, which can be a smaller visit than a full install. For the tricky parts, see plumbing installation and, if the disposal itself is the problem, garbage disposal repair.
If you smell gas anywhere near the kitchen, leave the building and call SoCalGas at 1-800-427-2200 from outside, or call 911. Nothing about a sink install is worth staying in a gas smell.
Nearby towns and how to reach us
Homeowners in San Bernardino, about 7.1 miles northwest of Loma Linda in a straight line, and in Highland, about 6.4 miles northeast, often ask the same questions about older kitchens. We serve both.
Stuck partway through a project, or with a leak after the first test? Call (909) 505-3225 on the 24/7 line. A licensed plumber can step in, and you hear a clear price before any work starts.
Sink and disposal questions
Yes, if you are comfortable with hand tools and the power is off. Most people struggle with the drain alignment and the electrical hookup, so do the plumbing only when you are sure of both.
Usually the bowl closest to the wall drain stub or the one with the deeper basin. The key is that its outlet lines up with the drain run and the trap, so check clearance before you buy.
The knockout plug in the disposal inlet may still be in place, or the drain hose may be pinched or sagging. Remove the plug with the power off and check the hose loop.
Permit rules vary with the scope of work, and the city pages do not name disposals. Ask the Loma Linda Building and Safety Division before you begin, especially if you plan to move a drain or add wiring.
It is not safe to assume so. With about 62 percent of households renting, most kitchens belong to someone else, and the lease usually decides who may change plumbing. Get written approval first.
Need a hand with the sink install?
Call the 24/7 line. A licensed plumber can take the job or finish it, with a clear price before work starts.
Call (909) 505-3225Dispatched from Loma Linda
Crews head out from Loma Linda to the neighborhoods below and the towns around them.