When does a furnace replacement make sense?
- A cracked heat exchanger or another safety failure.
- Repeated breakdowns, or a major part (inducer, control board, blower) on an old furnace.
- You are replacing the air conditioner: the new coil sits on the furnace, and an old blower can hold back a new AC.
- Uneven heat, high gas bills or a noisy, short-cycling furnace that tuning does not fix.
If your furnace is safe and the fault is a single part, repair it; see furnace repair.

Furnace types and efficiency (AFUE)
AFUE is the share of the gas a furnace turns into heat. Standard furnaces run about 80% AFUE and vent through a metal flue; condensing furnaces run 90% and above and vent through PVC pipe, which needs a drain and a vent route. Which one fits depends on the venting route and how many hours the furnace runs each winter. Variable-speed and two-stage models give steadier, quieter heat. In the South Coast region a new gas furnace also has to meet the air district's nitrogen oxide rule (Rule 1111).
Matching the furnace, coil and ducts
The furnace blower moves the air for heating and cooling. The furnace should be sized for the home's heat loss and its blower for the AC tonnage, with the existing coil checked against the new cabinet and the ducts looked at, because a new furnace on leaky or undersized ducts will be loud and uneven. Damaged ducts are covered on air duct replacement.

The installation process
- Free quote: the home, venting and gas line are looked at and the options explained.
- Removal of the old furnace; gas, power and venting made safe.
- New furnace set, connected to ducts, gas, venting, condensate (on condensing models) and thermostat.
- Start-up: gas pressure, temperature rise, venting draft and safety controls tested.
- Permit inspection and a walk-through of filter changes and maintenance.

What affects furnace installation cost?
Furnace size and efficiency, attic versus closet or garage location, venting changes for a condensing furnace, duct and gas line work, and the permit. Our pricing is up front, with no hidden fees. Considering electric heat instead? Compare with a heat pump installation or our heating installation overview.

What customers say
"Estimate Friday, Installation on Monday. Perfect transaction."
"The technicians were skilled and courteous, making the entire process stress-free. I highly recommend their heating installation services."
"Ernie's crew has replaced my HVAC system at a reasonable price. They are professional, patient and knowledgeable."
Furnace installation questions
How long does a furnace installation take?
It depends on the job: venting changes, new ducts or a furnace-plus-AC replacement take longer than a like-for-like swap.
Can the new furnace go in the same place?
Usually yes. Attic, closet and garage locations are all common; condensing furnaces need a drain and a PVC vent path.
Do I need a permit?
Usually yes: replacing a furnace generally needs a permit and an inspection from the city's building department.
