Short answer
Replacing a gas furnace in New Orleans means removing the old unit, setting a new one sized to the house, connecting the gas line, venting, ductwork, wiring and the AC coil above or below it, and testing combustion and safety controls. A furnace with a cracked heat exchanger should be replaced, not repaired. Because winters are mild, a heat pump or dual-fuel system is often worth pricing as an alternative.
When a furnace should be replaced
A cracked heat exchanger is the clearest case: it can let combustion gases into the air the blower moves, so the furnace should be shut down and replaced. Repeated control board, inducer and gas valve failures on an older furnace point the same way, as does a unit too large for the house that short-cycles all winter.
Replacement is also the moment to rethink the fuel. Winters here are short, so a heat pump can carry most of the heating, and a dual-fuel setup keeps gas for the coldest mornings. We install Carrier, Trane, Lennox, Goodman and Rheem furnaces and price the options side by side.
Gas furnace, heat pump or dual fuel
| New gas furnace | Heat pump | Dual fuel | |
|---|---|---|---|
| Needs gas service | Yes | No | Yes |
| Cooling | Separate AC | Built in | Built in |
| Coldest-day heat | Strong | Backup strips | Gas furnace |
| Best when | The AC is newer and gas is in place | AC and furnace both need replacing | You want gas backup with lower running costs |
What decides the cost of a new furnace
We have no sourced local range for gas furnace replacement, so here is what moves the price.
- Size and efficiency. Standard and high-efficiency furnaces differ in price and venting.
- Venting changes. A new vent or liner adds parts and labor.
- Gas line and connector. Old flexible connectors and shutoffs are replaced.
- Attic access. Tight hatches and long carries add time.
- Coil match. The AC coil may need adapting or replacing.
Replacing an attic gas furnace
Attic furnaces are common in local homes and bring their own steps: the old unit comes out through the hatch, the new one goes in on a level platform, and the vent has to run cleanly through the roof with the right clearances. We check the gas line and shutoff, replace old flexible connectors, size the vent for the new furnace, and set up the condensate drain on high-efficiency models. Then we test combustion, the safety controls and the temperature rise before handing it over.
Switching to a heat pump instead
If the furnace and the AC are both near the end, replacing them with a heat pump and air handler can make sense here: the heat pump cools in summer and heats on all but the coldest days, with electric strips as backup. If the AC is newer, a dual-fuel setup keeps a gas furnace for cold mornings and lets a heat pump handle the rest. We compare running costs, the condition of the gas line and venting, and available rebates before recommending one.
Furnace or heat pump in St. Tammany Parish
When the January 2025 snow reached as far as Slidell, furnaces across the area ran harder than they had in years, and the ones near the end of their lives showed it. For Tammany Electric customers in St. Tammany Parish who are weighing a heat pump instead of a new furnace, there is no heat pump rebate program, so the comparison rests on equipment price and running costs alone, and we lay those out plainly.
How a furnace replacement runs
- Inspect and sizeHeat exchanger, venting, gas line and the house's load.
- OptionsFurnace, heat pump or dual fuel, priced side by side.
- Remove the old unitGas off, old furnace and connector out.
- Install and ventNew furnace, gas connection, vent and drain.
- Test combustion and safetyFlame, draft, limits and temperature rise.
How long the house is without heat
A straight furnace swap is often finished in a day. Venting changes, gas line work or switching to a heat pump take longer, and we schedule the work for mild weather when we can.