Furnace Repair in Sacramento
If you smell gas or a carbon monoxide alarm goes off, leave the house first and call PG&E or 911 from outside. For everything else (no heat, cold air from the vents, a furnace that starts and stops) check the thermostat, the filter and the switch on or beside the furnace before you call anyone.
A Sacramento furnace has an easy life, then a hard morning
Most Sacramento homes heat with a gas furnace, with gas from PG&E and electricity from SMUD. The furnace sits idle from April to October, often in an attic that hits well above 120 degrees all summer, and then is asked to start on the first cold morning of the tule-fog season. That first start is when the faults show up. In the search data, furnace repair in Sacramento barely registers in June and July and climbs to its highest from October through January.
Checks before anyone visits
- Thermostat set to Heat, a few degrees above the room, with fresh batteries.
- The furnace power switch, which looks like a light switch on or near the unit, is on.
- The panel door on the furnace is seated properly. A safety switch keeps it off if the door is ajar.
- The filter is not clogged. A choked filter makes the furnace overheat and shut itself down.
- The flue and the intake pipes outside, on newer high-efficiency furnaces, are not blocked by leaves or a bird nest.
If it still will not light, look through the small window on the furnace for a blinking status light and count the flashes. The code chart on the inside of the panel door tells the technician where to start, and it is worth giving it on the phone.
What usually fails
Flame sensor
A thin rod that confirms the burners lit. A coating of residue makes it miss the flame, so the furnace lights, runs for a few seconds and shuts off. It is cleaned or replaced in minutes.
Hot surface igniter
The part that glows to light the gas. It is brittle and wears out, and the first cold morning after a long idle summer is when it cracks.
Inducer motor and pressure switch
The inducer fan clears the flue before the burners light, and the pressure switch proves it did. A noisy inducer, or a blocked condensate line on a high-efficiency furnace, keeps the furnace from lighting at all.
Blower and capacitor
The furnace lights and then shuts down on overheating because no air is moving. Same blower that runs the air conditioning in the summer.
The cracked heat exchanger question
A cracked heat exchanger can let combustion gases into the air the blower pushes through the house, so it is a real safety issue on an old furnace. It is also a diagnosis that has been used to sell furnaces that did not need replacing. If you are told the heat exchanger is cracked, ask to see it, on camera or through the burner opening, and ask for a carbon monoxide reading. A second opinion on a furnace replacement is reasonable and quick to get.
Repair, replace, or go electric
Furnaces in the older parts of Sacramento are often original to an addition or a 1990s replacement, and a twenty-five-year-old furnace with a failing inducer is near the end. If the furnace and the air conditioner are both old, replacing them together with a heat pump is worth pricing. SMUD's rebate for a gas-to-electric heat pump HVAC conversion is up to $3,000 in 2026, through SMUD Contractor Network companies, and a heat pump handles Sacramento winters, which rarely go much below freezing, without trouble. The heat pump page goes through the trade-offs.
What furnace repairs generally cost
Local companies generally quote a diagnostic visit in the same $90 to $200 range as an AC call. Flame sensor cleaning and igniter replacement are the cheap end, usually a few hundred dollars including the visit. Inducer motors, control boards and blower motors run into the mid hundreds to over a thousand. A heat exchanger is usually the end of the furnace's life rather than a repair.
If the house is cold and the furnace will not stay lit, call or send a request. A local heating and air company will call you back to arrange a visit.
Common questions
My furnace runs for a few seconds and shuts off. What is it?
Very often a dirty flame sensor. The burners light, the sensor fails to see the flame, and the board shuts the gas off as a safety measure. It is one of the quickest furnace repairs.
Why does my furnace smell when I first turn it on?
Dust that settled on the heat exchanger over the summer burns off. In Sacramento, where the furnace may sit unused for six months, that smell for an hour on the first cold day is normal. An electrical or plastic smell is not.
Is it worth repairing a 20-year-old furnace?
For a small part such as an igniter or a flame sensor, usually yes. For a heat exchanger or a combination of failures, usually not, especially if the air conditioner is the same age and a heat pump rebate is available.
Do I need a carbon monoxide alarm?
California law has required carbon monoxide alarms in single-family homes with a fossil-fuel appliance or an attached garage since 2011. If you have a gas furnace and no working alarm, fit one now.
Do you send someone out yourselves?
No. This site is an advertising and referral service. Your request goes to an independent local heating and air company that does the diagnosis and the work, and your agreement is with them.
Other heating and cooling help in Sacramento
- AC Repair in Sacramento, CA
- HVAC Repair and Diagnostics in Sacramento
- Heat Pump Repair and Installation in Sacramento
- Air Conditioner Replacement in Sacramento
Also serving
Furnace Repair is available beyond Sacramento, across Arden-Arcade , Carmichael , Elk Grove and Rancho Cordova .
Request furnace repair
Say what the system is doing and a local heating and air company will call you to arrange a visit. Calls answered Mon–Fri 7am–7pm, Sat 8am–4pm Or call (916) 237-9687, which is quicker when the house is already hot.