Furnace Installation in Buford & North Georgia

Southeast installs gas furnaces in Buford and the surrounding communities homes with a Manual J load calculation to size it, a matched Daikin single-stage, two-stage or variable-speed furnace, the permit pulled, a full startup, and the warranty registered for you.

What does a furnace installation include?

A furnace installation is the replacement of the gas furnace itself: the indoor unit that burns natural gas or propane and pushes warm air through your ducts. Sometimes it's the furnace alone. Often it's the furnace plus the evaporator coil that sits on top of it, or the furnace and the outdoor air conditioner together as a matched system. This page covers the install itself: what's in it, how we size it and what happens on the day. If you're still deciding whether to replace at all, start with furnace replacement.

Every Southeast furnace installation includes:

• Removal and disposal of the old furnace.
• The new furnace, set level and sealed to the supply and return plenums, with transitions fabricated where the new cabinet doesn't match the old duct openings.
• Venting: connecting to the existing flue for a standard furnace, or running PVC intake and exhaust for a high-efficiency (condensing) model.
• Gas line connection and leak test, and the condensate drain or pump a condensing furnace needs.
• Electrical connection, thermostat wiring and any new thermostat you've chosen.
• The permit, when the jurisdiction requires one, with the permit cost included in the quoted price.
• Startup and commissioning: gas pressure, temperature rise, airflow, safety-switch and combustion checks before we call it done.
• Manufacturer warranty registration, handled by our office.

Anything outside that, such as duct repair, a new gas line run or electrical panel work, shows up as its own line in the proposal so there are no surprises. We don't do new-construction installs, and we don't install boilers or oil furnaces.

How do you size a new furnace?

We run a Manual J load calculation on every replacement. Manual J is the industry method for figuring out how much heating a specific house needs, based on its square footage, insulation, windows, orientation, air leakage and climate. It replaces the guess most furnaces were sized with the first time: “put in what was there.”

Sizing matters more than most homeowners expect. A furnace that's too big heats the house in short bursts, shuts off, and never runs long enough to even out the temperature between rooms; it also cycles its parts far more often. A furnace that's too small runs nonstop during a cold snap and still loses ground. The right size runs longer, steadier cycles and is easier on the equipment.

The load calculation also tells us what airflow the ductwork has to deliver. If the existing ducts can't move that air, we say so during the estimate, because a new furnace bolted to a starved duct system is a problem waiting to happen. Our Learning Center article on Manual J goes deeper.

Which furnace should I choose: single-stage, two-stage or variable-speed?

Daikin is our primary brand, and we're a Daikin Premier Dealer. Within that lineup, the choice is about how the furnace runs, and each tier comes with a different Southeast labor warranty:

• Single-stage (1-year Southeast labor warranty). The burners are either fully on or off. Simple, dependable and the lowest cost. Right for a homeowner who wants a reliable replacement and doesn't need the comfort features of the tiers above.
• Two-stage (3-year Southeast labor warranty). The furnace has a low setting for mild days and a high setting for cold ones. Longer, gentler cycles on most winter days, with fewer temperature swings between rooms.
• Variable-speed (5-year Southeast labor warranty). The burner and blower adjust in small steps to match what the house needs at that moment. The quietest, most even heat, and the tier that pairs with the Daikin Fit inverter system (an outdoor unit whose compressor varies its speed) if you're replacing the outdoor unit too.

Manufacturer parts and unit-replacement coverage varies by tier and is subject to Daikin's written terms and registration. Qualifying single-stage equipment carries 12-year parts coverage and a 6-year unit replacement; qualifying Daikin Fit equipment carries 12-year parts and up to 12-year unit replacement. We put the exact coverage for your proposed equipment in writing. For the comparison in more depth, see the Daikin systems page.

Should I replace the air conditioner at the same time?

Not always, but it's worth pricing. The evaporator coil that cools your house sits on the furnace, and a new furnace often means a new coil. If the outdoor unit is also aging, replacing everything as one matched system means one crew visit, one permit, one startup and equipment designed to work together. All new Daikin systems we install use R-32 refrigerant. Our AC installation page covers that side, and a free estimate prices it both ways so you can decide with real numbers.

What happens on installation day?

By the time we arrive in Suwanee, Cumming or Milton, the decisions are made. You've had the free in-home estimate, seen the Manual J result, picked the tier, sorted financing if you're using it, and the permit has been pulled. Installation day is execution:

1. The crew, led by our lead installer, protects floors and the work area.
2. Gas and power to the old furnace are shut off, and the old unit comes out.
3. The new furnace is set, leveled and sealed to the ductwork, with new transitions fabricated as needed.
4. Venting, gas, condensate and electrical are connected, and the gas line is leak-tested.
5. The system is started and commissioned: we verify gas pressure, temperature rise, airflow and every safety control, and we let it run through full cycles.
6. Your thermostat is set up, and we walk you through the system, the filter and what to expect.
7. We haul the old equipment away and clean up.

Where the jurisdiction requires an inspection, we handle the required permit and the inspection that goes with it. Our office registers the manufacturer warranty, and your paperwork shows the exact equipment, coverage and labor warranty. Our permits and inspections article explains why that step matters. And if a problem is caused by our workmanship, Southeast will return and correct it at no charge.

Southeast is family owned and locally owned, run by owners Phillip Suggs and Brian Malone from our Buford office, licensed in Georgia under CR110452, and rated 5.0 on Google across 979 reviews as of September 2026.

How much does a furnace installation cost?

It depends on the house, and we won't pretend otherwise. What moves the number: the size the Manual J calls for, the tier you choose, whether venting has to change (a condensing furnace needs new PVC runs), gas line and electrical work, duct transitions or repairs, where the furnace lives (an attic install is more work than a garage one), and whether you're replacing the coil or the air conditioner at the same time. Removal, disposal, standard startup and the required permit are included.

The free replacement estimate gives you a written price for the options that fit. For planning, heating system payments start from $59 a month, and a complete heating and cooling system from $99 a month, with credit approval through Service Finance. Current programs include 18 months at 0% interest, 12 months with no payments and no interest, and 180 months at 9.99%; see financing for terms. You may qualify for up to $1,000 off a new system. Some restrictions may apply.

After the install, the Southeast Family Plan keeps the new furnace maintained on schedule, with two visits a year and 15% off qualifying repairs.

Get a free furnace installation estimate

Get a Free Replacement Estimate or call or text (770) 265-8308. We'll come out, measure the house, look at the ducts and venting, and give you real options in writing. If your home heats with a heat pump, or you're weighing the two, our heating installation page compares them, and everything heating-related starts at heating services.