Kitchen Sink Plumbing Toronto 2025: Installation & Repair Guide

Kitchen Sink Plumbing Components

Understanding the components helps diagnose problems and communicate with plumbers:

Water Supply Side

• Shutoff valves: Hot and cold angle stops under sink (should be 1/4-turn ball valves in modern installs)
• Supply lines: Braided stainless steel flexible connectors (replace if more than 10 years old)
• Faucet: Single-handle or two-handle, may include pull-down sprayer

Drain Side

• Basket strainer: Fits in sink drain opening, catches debris
• Tailpiece: Pipe from strainer down to P-trap (or garbage disposal)
• Garbage disposal: Optional, mounts under sink, grinds food waste
• P-trap: U-shaped pipe that holds water to block sewer gases
• Drain arm: Horizontal pipe from P-trap to wall drain connection
• Air gap / high loop: Dishwasher drain connection point

Kitchen Sink Installation Costs

Sink prices range from $100 (basic stainless single bowl) to $1,500+ (premium fireclay farmhouse). Most Toronto kitchens use double-bowl stainless sinks ($150-$400).

Common Kitchen Sink Problems & Fixes

1. Slow Draining Sink

The #1 kitchen plumbing complaint. Causes and solutions:

Grease buildup (most common): Toronto's cold pipes cause grease to solidify faster. Pour boiling water down the drain, followed by dish soap, then more hot water. For stubborn buildup, try baking soda + vinegar (1/2 cup each, wait 15 minutes, flush with hot water).

Clogged P-trap: Food particles and grease accumulate in the P-trap. Place bucket below, unscrew the two slip nuts, remove P-trap, clean thoroughly, reassemble. Takes 10 minutes.

Blocked drain line: If P-trap cleaning doesn't help, the blockage is further down. Use a hand crank drain snake or call for professional drain cleaning ($100-$200).

Garbage disposal issues: If you have a disposal, it may not be grinding effectively. Run disposal with cold water, try ice cubes to clean blades, check for jams.

2. Leaking Under Sink

Leaks under the kitchen sink have several sources:

Supply line connections: Check where braided lines connect to faucet and shutoff valves. Tighten gently or replace lines if corroded/old.

P-trap connections: Slip nuts can loosen over time. Hand-tighten, then give 1/4 turn with pliers. Check rubber washers—replace if cracked.

Basket strainer: Putty can fail after 10-15 years. Remove strainer, clean old putty, apply fresh plumber's putty, reinstall.

Garbage disposal: Leaks from disposal can come from top (mounting ring), side (dishwasher connection), or bottom (internal seal—replacement needed).

Faucet base: Water pooling at faucet base indicates failed O-rings or cartridge—faucet repair or replacement needed.

3. Low Water Pressure

Weak flow at the kitchen faucet:

Clogged aerator: Unscrew the aerator at the faucet tip, soak in vinegar to dissolve mineral deposits, scrub with toothbrush, reinstall. This fixes 80% of pressure issues.

Partially closed shutoff: Check valves under sink are fully open (counterclockwise to open).

Kinked supply line: Flexible lines can kink behind the sink, restricting flow. Straighten or replace.

Whole-house issue: If pressure is low at all fixtures, the problem is at the water main, pressure regulator, or municipal supply.

4. Sprayer Problems

Pull-down sprayers are common failure points:

Weak spray: Check for clogged spray head (soak in vinegar), kinked hose under sink, or diverter valve failure inside faucet body.

Won't retract: The weighted ball on the hose may have shifted. Adjust position or add a second weight.

Leaking at base: O-rings in the sprayer connection wear out. Replacement kits cost $10-$20.

Garbage Disposal Integration

Garbage disposals add complexity to kitchen sink plumbing but are worth it for convenience. Key considerations:

Dishwasher Connection

If you have a dishwasher, its drain connects to the garbage disposal inlet. Important points:

• Knock out the dishwasher inlet plug on new disposals before connecting
• Run dishwasher drain hose in a "high loop" under counter (prevents backflow)
• Some areas require an air gap device at the countertop
• Run disposal briefly after dishwasher drains to clear food particles

Double Bowl Sink Configuration

With a disposal on one side:

• Non-disposal side drains through a standard tailpiece
• Both drains connect to a tee fitting before the P-trap
• Disposal outlet is higher than opposite tailpiece—this is normal
• Continuous waste (horizontal pipe connecting bowls) must slope toward P-trap

DIY vs. Professional

DIY-Friendly Tasks:

• P-trap cleaning: Bucket, pliers, 10 minutes
• Aerator cleaning: Unscrew, soak, scrub, reinstall
• Supply line replacement: Turn off water, unscrew old, install new
• Basket strainer replacement: Putty, wrench, 30 minutes
• Faucet replacement: Moderate skill, follow manufacturer instructions

Call a Plumber For:

• New sink installation: Especially undermount or farmhouse styles
• Moving sink location: Requires extending drains and water lines
• Persistent slow drain: May indicate main line issues
• Garbage disposal installation: If electrical work is needed
• Water supply leaks at wall: Behind-wall repairs

Choosing a Kitchen Sink

Plumbing considerations when selecting a new sink:

Mounting Style

Drop-in (top mount): Rim sits on countertop. Easiest to install and replace. Works with any countertop material. Rim can collect debris.

Undermount: Mounted below countertop. Cleaner look, easy to wipe crumbs directly into sink. Requires solid-surface countertop (granite, quartz). More complex installation.

Farmhouse (apron front): Front of sink is exposed. Requires cabinet modification. Makes a strong design statement. Heavy—needs reinforced cabinet.

Bowl Configuration

Single bowl: More workspace for large pots/pans. Simpler plumbing. Popular in modern kitchens.

Double bowl (equal): Separate wash and rinse. One side for disposal, one for draining dishes. Classic configuration.

Double bowl (60/40): Larger main bowl with smaller secondary. Versatile option.

Material

Stainless steel: Most common, durable, affordable ($100-$400). Look for 18-gauge or thicker for quality.

Granite composite: Heat/stain resistant, quieter than steel ($200-$500). Heavier, requires undermount clips.

Fireclay: Classic farmhouse look, extremely durable ($400-$1,200). Very heavy, chips if heavy objects dropped.

Cast iron: Timeless, available in colors ($300-$800). Heavy, enamel can chip. Requires additional support.