A straightforward dishwasher replacement — swapping a new unit into the same cabinet space where an old one already existed — typically takes a licensed plumber or experienced installer between one and two hours. That includes disconnecting and removing the old unit, connecting the new one’s water supply line, drain hose, and electrical connection, leveling and securing the dishwasher, and running a test cycle. Installing a dishwasher in a location where there wasn’t one before is a longer project: plan on a half day to a full day, or more if new electrical work is involved.

What Affects Installation Time

The biggest variable is what the installer finds once they start working. Older Denver-area homes frequently have shut-off valves that don’t fully close, requiring valve replacement before the supply line can be connected. Corroded drain connections and mineral-cemented hose clamps (thanks to Colorado’s hard water) can add time to the disconnect phase. Hard-wired electrical connections take longer than cord-and-plug setups. And if the new dishwasher has different height or depth dimensions than the old one, adjusting the cabinet opening or countertop fit adds time as well.

Another factor: whether the drain connects to a garbage disposal or a dedicated drain tailpiece. If you’re adding a new disposal at the same time, or if the knockout plug inside the disposal needs to be removed before the dishwasher drain hose is connected, that adds a step — and a step that’s easy to miss if you’re doing this yourself (a missed knockout plug is one of the most common DIY dishwasher installation errors).

New Installation vs. Replacement: The Time Difference

A new-location dishwasher installation requires a plumber to run a new hot water supply line, install a drain connection with proper venting, and coordinate with an electrician for a dedicated 20-amp circuit. Each trade component takes time independently, and coordinating two trades means either a longer single visit or multiple visits. In most Colorado jurisdictions, a permit is required for new installations, and an inspection must happen before the wall or cabinet is closed up. This is a multi-hour, multi-trade project — not an afternoon task.

  • Same-space replacement: 1–2 hours for a licensed plumber in most cases
  • Replacement with complications (valve replacement, drain modification, electrical adjustment): 2–4 hours
  • New location installation requiring new supply, drain, and circuit: half day to full day minimum
  • Delivery timing matters — confirm your appliance delivery window so the plumber can arrive once the unit is on-site
  • Run a full cycle after installation and inspect under the sink and around the kick panel for any leaks before closing everything up

DIY vs. Professional: Does It Take Longer to Do It Yourself?

Almost certainly yes, especially if you’re doing it for the first time. An experienced plumber has done this dozens of times, has the right tools on the truck, and knows what to look for. A first-time DIY installation can easily stretch to four or more hours when you account for hardware store runs, troubleshooting unexpected issues, and the time to carefully read instructions. There’s also no buffer if something goes wrong — a supply line that won’t thread correctly or a junction box that’s wired unconventionally can halt a DIY job for hours while a professional would handle it in minutes.

If you want the dishwasher installed correctly and quickly, Done’s team can handle it as part of our kitchen and bath plumbing services. We’ll make sure the supply line, drain, and electrical are all connected to code — and we’ll run the test cycle before we leave. Contact us to schedule a convenient time that works around your appliance delivery.