If your furnace is 20 years old, has a cracked heat exchanger or needs a repair that costs a third of a new unit, replacement is usually the better value. A new furnace is quieter, safer and lighter on gas, and today it is also a decision about the next 20 years of how you heat your home.
What is included
- Load calculation and return-air check (undersized returns are common in Fremont tract homes)
- New furnace, filter rack and thermostat wiring
- Venting inspected and brought up to code, including liner or new flue when required
- Gas line, drip leg and seismic strapping where applicable
- City of Fremont mechanical permit and final inspection
- Combustion analysis and carbon monoxide test at startup
Gas furnace or heat pump?
A new gas furnace has a lower upfront price, especially if you keep your existing air conditioner. A heat pump costs more upfront but replaces both heating and cooling, works well in Fremont winters and avoids future gas rules. Our heat pump vs. gas furnace comparison runs the numbers for a typical Fremont home.
Ducts matter as much as the furnace
A new furnace on leaky, dirty ductwork will not deliver what you paid for. California energy code often requires duct testing when the furnace is replaced, and we include it. If the ducts are dusty or damaged, we may recommend duct cleaning or sealing as part of the job.
Typical costs in Fremont
| Job | Typical range |
|---|---|
| 80% gas furnace, like-for-like | $5,500–$8,000 |
| 96% high-efficiency gas furnace | $7,000–$10,000 |
| Furnace + AC together | $11,000–$19,000 |
| Ducted heat pump (replaces both) | $12,000–$24,000 |
Ranges reflect recent Fremont-area jobs and change with equipment, access and parts. You get an exact, written price before any work starts.
Looking for more than one fix? ComfortFlow is a full-service HVAC company in Fremont, so one call covers heating, cooling and hot water.