You've signed the quote, scheduled the install, and now you're wondering what your house is about to look like for the next day or two. Here's a walkthrough of what actually happens — from the truck pulling up to the moment we hand you the thermostat and walk you through everything.

Before installation day

After you sign your quote, we order your equipment. Most systems are in stock or available within a few days. We'll call you to schedule the installation date that works for your household.

A few things to do before we arrive:

Clear the area around your furnace, air handler, or wherever the indoor equipment lives. We need about 4–5 feet of working space. If that's in a utility closet full of holiday decorations, now's a good time to relocate the inflatable Santa.
Clear a path from the door to the equipment. We're carrying heavy equipment in and old equipment out.
If we're installing an outdoor unit, make sure the area along the exterior wall is accessible. Move planters, garden hoses, or anything within about 3 feet of where the unit will sit.
Let us know about pets. We love dogs — we have a photo of one on our website for a reason — but doors will be opening and closing throughout the day. If your dog is an escape artist or your cat makes a break for it every time the front door cracks, it's worth planning ahead.
You don't need to be home the entire time, but we do need access and someone available by phone. Many homeowners head to work and check in by text throughout the day.

What happens on installation day

Morning: the crew arrives

Expect our team between 8:00 and 8:30 AM. You'll see a Treat's truck (or two, depending on the job scope) and a crew of 2–3 installers in Treat's uniforms. We'll introduce ourselves, confirm the scope of work, and do a walkthrough with you before we start.

First thing we do: lay down floor savers and drop cloths along every path we'll use. Your floors, your carpet, your stairs — all protected before a single tool comes out.

Step 1: Remove the old equipment

The existing system gets disconnected, drained of refrigerant (which we capture and recycle — we never vent it), and removed. If it's a furnace, we disconnect the gas, flue, and electrical. If it's a heat pump or AC, we disconnect refrigerant lines, electrical, and the outdoor unit.

The old equipment leaves your home the same way the new equipment comes in — through the front door or garage, protected with blankets so it doesn't nick your doorframes.

How long this takes: 1–3 hours depending on the system and accessibility. Attic and crawlspace installations take longer than garage or utility room setups.

Step 2: Prep and modifications

This is where the custom work happens. Every home is slightly different, and the new equipment rarely has the exact same dimensions or connections as the old. Our team:

Fabricates custom ductwork transitions on-site using our mobile sheet metal shop (yes, we bring the shop to you). These transitions are built air-tight and sealed with mastic — not taped, not screwed-and-hoped-for-the-best.
Runs or modifies electrical connections to meet current code requirements and the new equipment's specifications.
Installs new refrigerant lines if needed, including a new filter drier (this protects the compressor from contamination).
Seals all penetrations — any new holes through your walls, roof, or foundation get caulked, patched, and sealed to protect against moisture and pests.

How long this takes: 2–4 hours. This is the longest part of the day and the part that separates a quality installation from a sloppy one. We don't rush this.

Step 3: Install the new equipment

The new indoor unit gets positioned, leveled, and connected to your ductwork, electrical, and (if it's a furnace) gas line. The new outdoor unit gets placed on a pad, leveled, and connected to refrigerant lines and electrical.

If your quote includes a new thermostat, it gets wired and mounted at this stage.

How long this takes: 1–2 hours.

Step 4: Start-up, testing, and commissioning

This is not "flip the switch and leave." We run a complete start-up procedure:

Verify gas pressure (furnaces) or refrigerant charge (heat pumps/AC) meets manufacturer specifications
Test all safety controls and switches
Measure airflow and temperature differential across the system
Verify the thermostat communicates correctly with the equipment
Run the system through heating and cooling modes
Document everything in a start-up report that meets both factory standards and Treat's standards

How long this takes: 30–60 minutes.

Step 5: Walkthrough and training

Before we leave, we sit down with you (or whoever will be living with the system) and walk through:

How to operate your thermostat — including scheduling, fan settings, and any smart features
What the filter is, where it is, and how often to change it
What normal operation sounds and feels like
When to call us vs. when to try a simple reset
Your warranty coverage and what's included

We don't leave until you're comfortable. If you think of a question next Tuesday, call us. That's what we're here for.

How long does the whole thing take?

Most residential replacements: 6–10 hours (one full day). Some larger or more complex jobs — like converting from a furnace to a heat pump with new line sets and electrical work — can stretch into a second day. We'll tell you the expected timeline before installation day so you can plan accordingly.

What your house looks like after

Honestly? Better than before. The new equipment is clean, properly mounted, and neatly connected. The area around it is swept. Our drop cloths are picked up. The old equipment is gone. If we cut into drywall for access, it's patched. If we drilled through your exterior wall, it's sealed and clean.

We take a lot of pride in leaving your home the way we'd want ours left. That's not a marketing line — it's the standard our crews are trained to and held to.

The first-year checkup

Every new installation includes a first-year checkup on us. We'll reach out around the one-year mark to schedule a visit where we inspect the system, verify everything is still operating correctly, and make any adjustments. This is included — no charge, no upsell.

After that, we offer Preferred Maintenance Plans that keep your system tuned up annually and give you priority scheduling and parts/labor discounts. But that's your call, not ours to push.

One last thing

Getting a new HVAC system installed is a big deal — it's one of the largest investments you'll make in your home. It's normal to have questions before, during, and after. We'd rather you ask too many questions than not enough. That's what we're here for.

What to Expect When You're Getting a New HVAC System Installed