What Affects Dishwasher Installation Cost

New Installation vs Replacement

The single biggest cost factor is whether this is a new installation in a kitchen that has never had a dishwasher, or a like-for-like replacement of an existing unit.

A straightforward replacement, where a working dishwasher is being swapped for a new model of the same size, typically costs $100 to $200 for installation labour. The plumber or installer disconnects the old unit, slides in the new one, connects to the existing water supply and drain lines, and tests it. The whole job usually takes 1 to 2 hours.

A new installation in a kitchen that has no existing dishwasher space is a different project entirely. It typically involves cutting a hole in the cabinetry or countertop, running a new hot water supply line, installing a drain connection at the sink drain or garbage disposal, and potentially running a dedicated electrical circuit. Total costs for a new installation commonly range from $500 to $1,500, depending on how much new plumbing and electrical work is required.

Plumbing Changes

If new plumbing is required, this adds substantial cost. Plumbing labour runs $50 to $150 per hour depending on location and the complexity of the work. Common plumbing additions for a new dishwasher installation:

• -New hot water supply line with shut-off valve: $100 to $250 materials and labour
• -Drain line connection to existing sink drain: $75 to $150
• -Air gap installation (required by code in some states): $50 to $100
• -Replacement of corroded or incompatible supply line connections: $50 to $150

For a replacement installation, these costs usually do not apply because the existing connections are reused. However, if the old unit's supply valve is seized or corroded, or if the drain connection is problematic, you may encounter unexpected plumbing costs even for a simple swap.

Electrical Requirements

Most dishwashers require a dedicated 15-amp or 20-amp 120V electrical circuit. If your kitchen already has a dishwasher, this circuit almost certainly exists. For new installations, adding a dedicated circuit can cost $200 to $500 depending on how far the panel is from the dishwasher location and whether the work requires running wire through walls or under floors.

In some cases, existing circuits can be used if there is sufficient capacity, but most licensed electricians will recommend and many local codes will require a dedicated circuit. Check your local permit requirements before starting a new installation.

Some newer dishwashers are hardwired directly to the electrical supply rather than using a plug. If you are replacing a hardwired dishwasher with a plug-in model or vice versa, there may be a small additional electrical cost to modify the connection type.

Countertop Type and Cabinetry

The type of countertop and cabinetry surrounding the dishwasher space affects installation complexity and cost. Standard laminate countertops present no special challenge. Stone countertops (granite, quartz, marble) are more complex because the mounting brackets that secure the dishwasher from above cannot be easily drilled through stone.

For stone countertops, installers typically use side-mount brackets that attach to the adjacent cabinet walls rather than the underside of the countertop. Most modern dishwashers include these side-mount brackets, but installation takes slightly longer and costs a little more.

If the dishwasher opening needs to be widened or narrowed (because you are switching from a compact 18-inch unit to a standard 24-inch unit, for example), cabinetry modification can add $200 to $800 to the project cost depending on the extent of the changes required.

Garbage Disposal Connection

If your kitchen has a garbage disposal, the dishwasher drain line typically connects directly to the disposal unit. This is usually a straightforward connection, but if the disposal needs to be removed or replaced as part of the project, the additional cost is $150 to $350 for disposal removal and replacement.

If you do not have a garbage disposal, the dishwasher drain connects to the main drain line, either through a dedicated fitting on the P-trap or through a Y-fitting installed on the drain. This is slightly more work than connecting to a disposal but is standard practice and should not add significantly to the cost.

Old Unit Removal and Disposal

Removal of an old dishwasher is often included in the installation quote but not always. Confirm this before hiring an installer. If it is not included, disposal fees of $25 to $75 are typical. Many appliance retailers that sell you a new dishwasher will haul away the old one for free or a small fee as part of the delivery.

Older dishwashers (pre-2000s) may contain materials that require specific disposal. Your installer or local recycling centre can advise on the right approach in your area.

Geographic Location

Labour rates vary significantly by location. In major metropolitan areas on the coasts, plumber or installer rates of $100 to $150 per hour are common. In mid-sized cities and suburban areas, $60 to $100 per hour is more typical. Rural areas vary more widely depending on local competition and availability.

Get three quotes before committing to any installer. Use our homepage calculator to estimate your total project cost based on your specific situation.