Furnace Replacement in Charleston, SC

Furnace replacement in Charleston makes sense when the furnace is unsafe or a repair no longer buys useful time, and not much sooner. Aero Air Techs tests the furnace, shows you what we found and lays out your options on paper. Short winters are kind to burners, so plenty of old furnaces here still have years left. Others do not.

If yours has one failed part, start with furnace repair. This page is for the furnace that has stopped earning another repair.

When is furnace replacement in Charleston the right call?

Decide from the failure, then the age. Replacing a sound furnace too early wastes money, and keeping a cracked one is a safety problem.

The situation	Where it usually lands
Failed igniter, flame sensor or capacitor	Repair
Blower motor on a furnace in sound shape	Repair, after checking the age of the AC
Confirmed cracked heat exchanger	Replace, once you check manufacturer warranty coverage
Heavy rust at the burners or cabinet	Compare both in writing
Repeat repairs over the last few winters	Compare both, and recheck the sizing
Parts no longer available	Replace
Furnace and AC both near the end of their run	Price a full system or a heat pump

Ask for evidence before anyone condemns a furnace. A rusty cabinet or an old age sticker is not a failed heat exchanger, and it is fair to get a second opinion while the furnace stays off.

Age alone settles nothing. An old furnace upgrade only pays when it solves a real problem, like a safety fault or a house that never heats evenly. Our climate cuts both ways, because a furnace sees few burner hours here, yet it sits in humid air the rest of the year and its blower works all summer.

Furnace replacement cost: what moves the number

Scope moves the price more than the furnace itself. These are the items to look at first.

• Fuel path. Like-for-like is simplest. Changing fuel means new supply work.
• Efficiency tier. A condensing furnace costs more and needs plastic venting and a drain.
• Blower type. Variable-speed models cost more and help with humidity control in cooling season.
• Location. Attic platforms and tight closets take more labor than an open utility room.
• Duct and vent condition. An old metal flue may not suit the new furnace.
• The AC match. The new blower has to suit the coil you keep.

We quote your home before any work begins. For third-party ranges, dated and attributed, read our furnace replacement cost guide.

Keep gas, or switch to a heat pump?

Keep gas when the AC is young and the gas service, venting and drain are already in place. Look hard at a heat pump when the AC is aging too, or when your current furnace is electric.

Gas to gas

This is usually the simplest job, because the fuel supply and much of the venting already exist.

Electric furnace to electric furnace

It is simple to install and costly to run during a cold snap. It may suit a house with very little heating demand, but ask for a heat pump price before you commit.

Furnace to heat pump

A heat pump installation replaces your heating and your cooling with one system. About 71% of South Carolina households already heat with electricity, per EIA's 2023 state data, so this is a well-trodden path here. Heat pumps also keep working year-round, which matters on salty lots, so factor in outdoor unit care near the water.

Rebates can shift this math. Dominion Energy South Carolina's electric furnace to heat pump rebate has been reported at $650 for 2026, so confirm that on Dominion's page. Santee Cooper's home rebate program is a second one to check: reports put it at $300 to $400 per system, for Santee Cooper customers only. Our South Carolina rebate guide lists what to check.

Is a high efficiency furnace worth it in a mild climate?

Often not on fuel savings alone. AFUE shows how much of the fuel's heat reaches your house, so a 96% furnace wastes less than an 80% one. With short heating seasons, though, that gap pays back slowly here compared with a cold state.

A high efficiency furnace can still earn its place. Quieter operation, steadier temperatures and a variable-speed blower all help, and the blower benefit carries into cooling season. If those matter to you, price it. If the only reason is a payback claim, ask to see the math for Charleston's weather.

Federal rules are worth a quick check. DOE's minimum for non-weatherized gas furnaces in the South has been 80% AFUE. A DOE rule published in December 2023 raised the standard for future furnaces, and sources conflict on where that stands, so confirm the current federal minimum with DOE or your contractor. Furnaces already in homes are not affected.

Tax credits are off the table. The Section 25C credit ended with equipment placed in service by December 31, 2025.

What belongs in a furnace replacement quote?

Totals only help when the scopes match. Ask every bidder to put these in writing.

1. Model number, AFUE and capacity for the new furnace.
2. A load calculation, or the reason there is none.
3. Whether the AC coil stays, and proof it suits the new blower.
4. Venting changes, including any liner, new flue or PVC route.
5. Gas, electrical and condensate work.
6. Thermostat changes, if your thermostat needs replacing.
7. Removal of the old furnace, permit handling and manufacturer warranty terms.

Have every bidder give you a license number, then run it through the SC LLR lookup. A lower number with no load calculation and no venting plan is a different job.

How a furnace swap runs

A like-for-like swap is usually a one-day job, and it follows a set order.

1. Protect the path. We cover floors and shut off gas and power.
2. Disconnect the old furnace. Gas, flue, ducts, wiring and drain come apart.
3. Move it out. Attic and closet furnaces often come out in pieces.
4. Set the new furnace. It goes in level, with service clearance.
5. Reconnect. Gas joints are leak tested, ducts are sealed and venting is checked for slope and fit.
6. Commission it. We measure gas pressure, temperature rise and airflow against the manufacturer's numbers.
7. Hand it over. You get the paperwork and see how the filter and thermostat work.

Permits vary by town and county, so call the office for your address and get the permit plan written into the quote.

Why call Aero Air Techs about a tired furnace?

You should get a straight read, even when the answer is one more repair.

• 4.9★ on Google (16 reviews). Figure from October 2026.
• Plain talk. One customer described Cris as "communicative, transparent, knowledgeable, and punctual."
• Quotes you can compare. Another review notes "price were as quoted."
• On the clock around you. Our Google listing shows open 24 hours.

Replacing furnaces around Charleston

Our furnace replacements reach Hanahan, North Charleston, Mount Pleasant and the surrounding areas from our Charleston base. Have the model number handy when you phone, if you can find it, and we can start from there.

A replacement quote should answer the local question first.

• Hanahan: will the new unit fit the closet, with service clearance on all sides?
• Mount Pleasant: does each floor have its own furnace, and do both need replacing now?
• North Charleston: is the old flue sized for the new model, especially in an older cottage?
• Summerville: with frost as early as mid-November, can the swap happen before the first cold week?
• Moncks Corner: is your electric utility Dominion, Santee Cooper or Berkeley Electric? A heat pump rebate depends on that.
• Goose Creek: does the city's permit list call for a mechanical permit on your job?
• Ladson: which of the three counties holds your address, and who issues the permit there?
• James Island: is a crawlspace furnace in a flood zone that sets a new height?
• Walterboro: older porch-front homes may lack duct room, so does a heat pump or ductless option make more sense?