What to Expect When Your New Furnace Is Installed: A Complete Homeowner Checklist

Getting a new furnace installed can feel overwhelming — but knowing exactly what to expect at each stage makes the process smooth and ensures you don't overlook anything important. This checklist covers everything from delivery to first heat.

Before Installation Day: Preparation Checklist

• Clear 3 feet of clearance around the furnace area and along the path from your entry door to the mechanical room. Installers need to remove the old unit and bring in the new one without obstacles.
• Locate your electrical panel and confirm you know where the furnace breaker is. You should be able to easily toggle it off/on.
• Know your gas shutoff valve location — typically a lever handle on the gas line feeding the furnace. Verify it's accessible and operable.
• Document your current thermostat wiring — take a clear photo of the wires and their terminal labels before anyone touches it. This helps if wiring questions come up during installation.
• Confirm the permit situation — in Minnesota, a furnace replacement permit is required in most jurisdictions. Ask your installer whether they're pulling it. You want the work inspected.
• Have your model/spec documentation — if you ordered equipment factory-direct, have the spec sheets available so the installer can confirm compatibility.

Day of Installation: What Actually Happens

Step 1: Shutoff and Removal (1–2 hours)

The installer will shut off gas, shut off electrical power to the unit, and disconnect the flue/vent piping. The old furnace is disconnected from the duct system, gas line, and condensate drain (on 90%+ units), then removed from the space.

The old furnace will be hauled away by the installer — confirm this in advance so it doesn't end up sitting in your garage.

Step 2: New Unit Positioning (30–60 min)

The new furnace is moved into position. Installers verify it's level (critical for condensate drainage on high-efficiency units), and that clearances to combustibles meet the manufacturer's specifications (typically marked on the furnace label).

Step 3: Gas and Electrical Connections (1–2 hours)

Gas line is reconnected (may require a new flex connector — typical on replacement work). Electrical is wired to the furnace, including the 120V power supply and the low-voltage thermostat wiring. If upgrading from a simple thermostat to a smart thermostat with a C-wire requirement, this is when the C-wire gets added.

Step 4: Venting / Flue (varies by system type)

• 80% AFUE furnaces: Vent through existing metal B-vent flue. Usually straightforward swap-in.
• 90%+ AFUE condensing furnaces: Use PVC pipe vented through the sidewall (not the chimney). If replacing an 80% unit with a 96%, new PVC vent pipes need to be run to an exterior wall. This adds time (1–3 hours) but is standard practice.

Important: the old chimney flue may be abandoned. If a gas water heater previously shared the chimney, it may need its own flue liner installed — confirm with your installer.

Step 5: Condensate Drain (90%+ AFUE only)

High-efficiency furnaces produce condensate (water) during operation — up to 5 gallons per day in cold weather. The condensate drain must connect to a floor drain, utility sink, or condensate pump. Confirm this connection is secure and the drain flows freely.

Step 6: Startup and Commissioning (1 hour)

The installer fires up the unit for the first time:

• Checks for gas leaks at all connections (soapy water test or electronic detector)
• Verifies ignition sequence is working properly
• Checks for proper flue draft
• Measures supply air temperature (should be 50–70°F above return air for a properly operating furnace)
• Sets thermostat to call for heat and confirms full operation cycle

What to Verify Before the Installer Leaves

• ✅ Warranty registration — Goodman requires registration within 60 days for the 10-year parts warranty. Get the serial number and register at goodmanmfg.com (or ask if the installer will do it)
• ✅ Permit inspection scheduled — if a permit was pulled, a city/county inspector will need to inspect the work. Get the inspection date or process.
• ✅ Condensate drain tested — pour water into the condensate drain to verify it flows, especially if a condensate pump was installed
• ✅ Thermostat tested in both heat and cool modes
• ✅ Old furnace removed from property — confirm it's in the truck
• ✅ Installer documentation — get a copy of the installation record, equipment serial numbers, and any warranty paperwork
• ✅ Filter location explained — confirm you know where the new filter goes and what size to buy

First Heating Season: Normal Events

When a new furnace runs for the first time in heating season, a few things are completely normal:

• Burning smell on first run — factory oils and dust on the heat exchanger burning off. Normal for first 2–3 hours of operation, then gone permanently.
• Clicking from new ductwork — ducts expand and contract with temperature changes. Usually settles within a few days.
• Condensate dripping sounds — on 90%+ AFUE units, you'll occasionally hear condensate flowing. Normal.

Ordering Factory-Direct: How Furnace Direct Works With Installers

When you order factory-direct from Furnace Direct:

1. Equipment ships to your home or directly to the installer's location (your choice)
2. You hire a local licensed HVAC installer for the labor portion
3. Installation proceeds exactly as described above — same process as if a contractor supplied the equipment
4. You save $800–$2,500 on equipment vs. full-service contractor pricing, while getting full manufacturer warranty coverage

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