Most Central Texas homes with gas heat have a furnace in the attic, a closet or the garage, paired with an air conditioner that shares the same blower and ductwork. When a furnace is old, unsafe, or failing repeatedly, replacement becomes the question. This page explains what to consider. Requests sent through this site go to an independent contractor licensed by the Texas Department of Licensing and Regulation (TDLR). We don't install equipment.
Signs it may be time
- A technician finds a cracked heat exchanger or another safety problem that can't be reasonably repaired.
- Repeated ignition, flame sensor or control board failures.
- The furnace is old enough that parts are hard to find.
- You're replacing the air conditioner anyway, and the furnace's blower and cabinet should match the new system.
A cracked heat exchanger is a serious finding because it can allow combustion gases into the airflow. It's also a finding some homeowners like to confirm, and asking to see photos or a camera view is reasonable.
Gas furnace, heat pump, or both?
- Gas furnace with AC. Delivers warm air quickly. Operating cost depends on your local gas and electric rates.
- Heat pump with electric backup heat. One system handles both cooling and heating. In mild Central Texas winters it can be a good fit, especially where gas isn't available.
- Dual fuel. A heat pump handles most heating, and the gas furnace takes over in colder weather.
Which costs less to run depends on your actual utility rates, so ask the contractor to show the comparison with your numbers instead of a general claim. See our heat pump installation page for more.
Efficiency (AFUE)
Furnace efficiency is rated in AFUE, the percentage of fuel energy that becomes heat in the home. Standard furnaces vent through a metal flue. High-efficiency condensing furnaces vent through plastic pipe and produce condensate that must drain. In an attic install, that drain needs to be protected and properly routed. In a short heating season, the extra cost of a high-efficiency model may take a long time to pay back, so ask for both options.
What a good installation includes
- A load calculation and correct sizing, not simply matching the old nameplate.
- Correct gas piping, a sediment trap, and a leak test.
- Proper venting and combustion air, with clearance to combustibles.
- A secondary drain pan or float switch for attic installs.
- Carbon monoxide alarms in the home. Texas code and many cities require them with fuel-burning appliances.
- Permits and inspections where your city requires them.
How a request works
Tell us your town, the age of the current system, and whether you have gas service. We'll forward your request to an independent licensed contractor serving your area, who will assess the home and quote options.
Furnace Installation & Replacement FAQs
Gas furnace or heat pump in Central Texas?
Both work here. Which costs less to run depends on your gas and electric rates. Ask the contractor to compare using your actual rates rather than general claims.
Is a high-efficiency furnace worth it here?
With a short heating season, the payback on a condensing furnace can be long. Ask for quotes on standard and high-efficiency models and compare.
Should the furnace be replaced with the AC?
They share a blower and are often replaced together so the system is matched and rated correctly. A newer furnace in good shape can sometimes stay.
What about an attic furnace?
Attic installs need a secondary drain pan or float switch, safe access, and proper venting. Condensing furnaces also need condensate drain protection.
Is a permit needed for a furnace?
Usually, especially when gas piping or venting is involved. Rules vary by city. The licensed contractor normally pulls it.