HVAC Replacement Cost in Marietta, GA: 2026 Guide
When an aging AC or furnace in Marietta finally gives out, the choice between repairing again and replacing the whole system becomes urgent. This guide walks through what full HVAC replacement costs in the Atlanta metro, how heat pumps compare to gas furnaces here, and what permitting and licensing steps to expect.
By Homeowner Henry · HVAC · Published September 17, 2026 · 9 min read
What drives replacement cost in Marietta
System size matters most: most Marietta homes need a 2.5- to 4-ton system, and larger homes or those with poor insulation may need bigger equipment, which raises cost.
Efficiency rating is the next factor. A baseline 14-15 SEER2 system costs less upfront than a high-efficiency 18+ SEER2 unit, but the higher-efficiency option can pay back some of that difference in lower summer electric bills given how many hours AC runs here.
Ductwork condition also affects total project cost. Because so many Marietta homes route ducts through hot attics, a contractor may recommend duct sealing or partial replacement alongside the new equipment, which adds to the estimate but improves comfort and efficiency.
AC and heat pump replacement pricing
A straightforward AC condenser and coil replacement (matching to an existing furnace) for a typical 3-ton system runs roughly $4,500-$7,500 in the Atlanta metro.
A full heat pump system replacement, including both the outdoor unit and indoor air handler, typically runs $5,500-$9,500 depending on efficiency tier and ductwork condition.
Given Marietta's mild winters, many homeowners replacing an aging AC-plus-furnace setup choose to switch to a heat pump instead, especially if the existing furnace also needs replacement soon. See our hub page for a full local cost table.
Furnace replacement and dual-fuel setups
A standalone gas furnace replacement generally runs $3,800-$7,000 in this market, depending on efficiency rating and ductwork modifications needed.
Dual-fuel systems, pairing an electric heat pump with a gas furnace as backup for the rare hard freeze, cost more upfront than a single-system replacement but can lower monthly operating costs by using the heat pump for most of the mild Marietta winter.
If you're deciding between a straight AC/furnace swap and switching to a heat pump or dual-fuel setup, ask your contractor for a load calculation (a Manual J calculation) rather than a rule-of-thumb sizing estimate.
Permits, inspections, and licensing
Full system replacement requires a mechanical permit in both the City of Marietta and unincorporated Cobb County; confirm your jurisdiction before getting quotes, as explained on our hub page.
Only a contractor holding an active Georgia Conditioned Air Contractor license (Class I or Class II depending on system size) can legally pull the permit and perform the installation.
After installation, expect at least one inspection before the permit is closed out; Cobb County in particular asks that HVAC and plumbing inspections be scheduled together when both trades are involved on the same project.
Rebates that can offset replacement cost
Marietta Power and Water customers converting from gas to an ENERGY STAR electric or dual-fuel heat pump, or upgrading to a more efficient electric heat pump or AC unit, can apply for a utility rebate.
Georgia Power customers may instead qualify for rebates through the Home Energy Improvement Program, which can offset costs for heat pump conversions, duct sealing, and attic insulation when work is done by a program-affiliated installer.
Ask your contractor to help identify which rebates apply to your specific utility provider and planned upgrade, since terms and amounts vary and are updated periodically.
Ready to get quotes? Get matched with an HVAC contractor near Marietta for your replacement project.
Comparing quotes for a replacement project
Get at least three quotes for a full replacement, and make sure each includes equipment brand and model, SEER2/HSPF2 ratings, ductwork scope, and permit fees.
Watch for quotes that skip a load calculation altogether; oversized or undersized equipment is a common source of comfort complaints and higher bills after a replacement.
For help vetting contractors themselves, see our guide on how to choose an HVAC contractor in Marietta.
Typical cost ranges
| AC condenser + coil replacement (3-ton) | $4,500 - $7,500 |
| Full heat pump system replacement | $5,500 - $9,500 |
| Gas furnace replacement | $3,800 - $7,000 |
| Dual-fuel system (heat pump + gas furnace) | $7,000 - $11,000 |
| Ductwork repair/replacement (partial, attic) | $1,500 - $4,500 |
| New thermostat (smart/programmable) | $150 - $400 |
| Mechanical permit fee | varies by jurisdiction and scope |
Ranges are general estimates gathered from homeowner-reported quotes, not an offer or a quote for your project.
Common questions
How much does a full AC replacement cost in Marietta?
A typical 3-ton AC condenser and coil replacement runs $4,500-$7,500 in the Atlanta metro, depending on efficiency rating and installation complexity.
Is a heat pump a good choice in Marietta's climate?
Yes, Marietta's mild winters make heat pumps a practical primary heating and cooling source for most homes, and they're increasingly common in new installations.
Do I need a permit to replace my whole HVAC system?
Yes, full system replacement requires a mechanical permit from either the City of Marietta or Cobb County, depending on your property's jurisdiction.
What size system does my Marietta home need?
Sizing should be based on a Manual J load calculation, not just square footage, since insulation, duct condition, and window exposure all affect the correct size.
Are there rebates for replacing my HVAC system in Marietta?
Marietta Power and Water and Georgia Power both offer rebate programs for qualifying heat pump conversions and efficiency upgrades, though terms depend on your utility provider.
How long does a full HVAC replacement take?
Most residential replacements are completed in one to two days, though ductwork modifications or dual-fuel conversions can extend the timeline.
What license should my installer have?
Look for an active Georgia Conditioned Air Contractor license, Class I or Class II depending on system size, issued by the State Construction Industry Licensing Board.
Want real numbers for your own project?
Two minutes now beats a week of no cooling. Free, no obligation, never more than three HVAC contractors.
Get My Free HVAC QuotesLocal cost ranges, seasons, permits and licensing for this city live on the market page.
HVAC companies in Marietta, GASources
The Henry Standard
Every HVAC contractor in our network agrees to three things.
Show up
Call back. Keep appointments. And if something changes, communicate it.
Quote honestly
Equipment, scope, permit, and price in writing — so you know what you're agreeing to.
Finish the work
See the job through, pull the permit, and pass inspection before calling it finished.
Nothing revolutionary. Just the way we believe doing business should still be done.