On this page
There is no honest flat price for a new furnace. Two Los Angeles homes with the same size furnace can get very different estimates because the cost depends on the equipment, where it sits, how it vents, the condition of the ducts, the electrical work, permits and whether the air conditioner or a heat pump is part of the same project. This guide explains each cost factor so you can read a furnace estimate and compare quotes on the same scope.
The main furnace cost factors at a glance
Gas furnace replacement cost: the equipment
Size. A furnace should be sized to the heating load of the house, not copied from the old unit. Many older Los Angeles furnaces are oversized for today's insulation and windows. A load calculation can point to a smaller unit, which can change the equipment cost and how comfortable the house feels.
Efficiency (AFUE). Standard-efficiency furnaces vent through a metal flue. High-efficiency condensing furnaces capture more heat, vent through PVC pipe and produce water that needs a drain. In a mild climate, the payback on a higher-efficiency furnace depends on how much you heat and on gas rates, so it is worth asking for both options on the same estimate.
Burner and blower. Single-stage furnaces run at one output. Two-stage and modulating furnaces adjust their output, and variable-speed blowers adjust airflow. These features usually cost more and are quieter and steadier, especially when the furnace also moves air for central AC.
Location, venting and gas
- Attic, closet, garage or crawlspace. Access affects labor. Attic furnaces need a safe platform and walkway, and a secondary drain pan where a condensing unit or an AC coil sits above living space.
- Orientation. Upflow, downflow and horizontal furnaces are not interchangeable. Changing orientation or moving the furnace adds sheet metal and venting work.
- Venting. Moving from a standard furnace to a condensing furnace usually means new PVC vent and intake piping and a condensate drain. An existing metal flue may also need repair or replacement to meet code.
- Gas line and combustion air. A larger or relocated furnace may need a resized gas line, and closet installs need proper combustion air.
Furnace installation cost vs replacement
A like-for-like replacement reuses the existing ducts, gas line, vent path and electrical circuit, so it is usually the simplest scope. A new furnace installation, such as in an addition or a home that has never had central heat, may need new ductwork, returns, a gas line, venting, a circuit and a thermostat run. Those items are often a larger share of the estimate than the furnace itself.
Ductwork, electrical, permits and ECC
Ductwork. A new furnace cannot fix leaky, crushed or undersized ducts. Duct sealing, added returns or duct replacement can be part of the job, and in older homes they often matter more to comfort than the furnace upgrade. See duct sealing and replacement for what that work involves.
Electrical. A gas furnace still needs a dedicated circuit for its blower and controls. A switch to a heat pump can also involve a new outdoor circuit and a review of panel capacity.
Permits and ECC field verification. Furnace replacements in Los Angeles generally need a mechanical permit and inspection from the city or county building department. Depending on the scope, California's energy code can also require duct leakage testing and ECC field verification, formerly referred to as HERS testing. A complete estimate should say which of these apply to your job.
Furnace vs heat pump: cost considerations
A heat pump replaces the heating side of a furnace and also provides cooling, so the comparison is fairest when the air conditioner is part of the decision. If your AC is old or failing, one heat pump system can take the place of both a new furnace and a new AC. If your AC is new, a furnace-only replacement or a dual-fuel setup may make more sense.
- Equipment and indoor unit. A ducted heat pump usually pairs with an air handler; a dual-fuel system keeps a furnace as backup heat.
- Electrical. Heat pumps can need panel and circuit work that a gas furnace does not.
- Operating cost. This depends on your gas and electric rates and how much you heat and cool.
- Rebates. Heat pump rebates may be available subject to program rules and eligibility. LADWP customers can start with our LADWP heat pump rebate guide. The federal 25C credit is not available for 2026 installations. Home Upgrade Specialist is not a tax advisor; consult your tax professional.
For the full planning steps, see switching from a gas furnace to a heat pump and heat pump installation in Los Angeles.
How to compare furnace estimates
- Model numbers, AFUE, burner stages and blower type for the furnace offered
- How the size was chosen, and whether a load calculation was done
- Venting, gas line, drain and platform work included
- Duct sealing, repairs or replacement, and which are optional
- Electrical work, thermostat and any AC coil or heat pump changes
- Permit, inspection and any ECC field verification
- Removal and disposal of the old furnace, startup checks and warranty registration
Our furnace replacement scope checklist goes through each line item. If the furnace may be repairable, compare the estimate with heater and furnace repair first.
FAQ
What makes one furnace estimate higher than another?
Usually the scope, not the furnace. Venting changes, duct work, electrical, permits, a different efficiency level or an AC replacement in the same job can all separate two quotes for the same size furnace.
Does a high-efficiency furnace cost more to install?
Often, yes. Condensing furnaces typically need new PVC venting and a condensate drain, and the equipment itself usually costs more than a standard-efficiency model.
Is a new furnace installation more expensive than a replacement?
Usually. A replacement can reuse the existing ducts, gas line, vent and circuit, while a new installation may need some or all of them added.
Is a heat pump more expensive than a gas furnace?
It depends on the home and whether the AC is also being replaced. A heat pump can take the place of both a furnace and an AC, so compare the full heating and cooling scope, not one unit.
Why don't you list a flat furnace price?
Because the equipment, access, venting, ducts and permits change from home to home. We give a free written estimate after reviewing the house so the price matches the actual scope.
Get a furnace price for your home
Home Upgrade Specialist (CSLB #1031989) reviews your furnace, venting, ducts and electrical and gives you a free written estimate for furnace replacement or a heat pump.
Call (833) 446-6387 or text us.
Start your HVAC planRelated HVAC guides
Plan your home energy project with one team
Compare scope, equipment and utility rules in a single written plan built around your address.
Start My Home Plan