The short answer
If your furnace blows cool air, short-cycles, makes new noises, or won't light, PrimeAir HVAC Repair Service will diagnose the cause and give you a price before any work begins. Most furnace problems can be repaired, and Bay Area air quality rules don't require you to replace a furnace that still works.
When your furnace stops heating, short-cycles, or starts making noises it never made before, you want a clear answer about what's wrong and what it will take to fix it. PrimeAir HVAC Repair Service repairs gas furnaces for homeowners in Fremont and nearby cities, including Newark, Union City, and Milpitas. Winters around the Bay are mild and damp, so many furnaces sit idle for months and then get pushed hard on the first cold nights. That stop-and-start pattern is when worn parts, dirty sensors, and clogged filters tend to show up. We find the actual problem, explain your options in plain terms, and offer 24/7 emergency service when heat can't wait.
Signs Your Furnace Needs Repair
Some furnace problems are obvious, like no heat at all. Others build slowly and are easy to ignore until they turn into a breakdown on a cold night. Schedule service if you notice any of these:
If your carbon monoxide alarm sounds or you smell gas (a rotten-egg odor), don't try to troubleshoot. Get everyone out of the house, call your gas utility or 911 from outside, and have the furnace inspected before it runs again.
- The furnace runs but blows cool or lukewarm air
- It turns on and off every few minutes (short-cycling)
- Some rooms stay cold while others warm up
- Banging, squealing, rattling, or scraping sounds when it starts or runs
- The blower runs nonstop, or doesn't come on at all
- The igniter clicks repeatedly but the burners don't light
- A burning smell that lasts beyond the first few minutes of the heating season
- Gas bills climbing even though you haven't changed how you use heat
- Your carbon monoxide alarm goes off
What We Check During a Furnace Repair Visit
A furnace that won't heat can fail for a dozen different reasons, and replacing parts by guesswork wastes your time and money. Our technicians work through the system in order, from the thermostat to the vent, so the repair fixes the cause and not just a symptom.
Once we find the problem, we show you what we found, explain what the repair involves, and give you a price before any work starts.
- Thermostat settings, wiring, and batteries
- Air filter condition and airflow through the return
- Igniter or pilot assembly and flame sensor
- Gas valve operation and burner flame
- Blower motor, capacitor, and blower wheel
- Limit switches, pressure switches, and control board error codes
- Inducer motor and venting, checked for blockages or loose connections
- Heat exchanger, inspected for cracks or corrosion
- Condensate drain and trap on high-efficiency furnaces
- Duct connections at the unit for obvious leaks
Repair or Replace Your Furnace?
Most furnace problems are worth repairing. A failed igniter, dirty flame sensor, weak capacitor, or tripped limit switch is usually a straightforward fix that keeps the furnace running for years. Replacement starts to make sense when a major repair is needed on an older furnace, when the heat exchanger is cracked, when the same parts keep failing, or when parts for your model are hard to find.
Bay Area air quality rules are worth understanding, but they shouldn't rush your decision. The Bay Area Air District's appliance rules do not require you to replace a working furnace; they apply only when an existing furnace fails or is replaced. Under Rule 9-4, natural gas furnaces manufactured starting in 2029 must meet a zero-NOx emission standard, which in practice points homeowners toward heat pumps when they replace a furnace after that date. If your furnace is aging, that timeline can help you decide whether to keep repairing it or start planning for a heat pump.
If you're considering a heat pump, keep in mind that the federal Energy Efficient Home Improvement Credit (25C) only covered qualifying heat pumps placed in service before December 31, 2025, so it isn't available for new installations. Bay Area homeowners can still check BayREN and their local clean energy provider for heat pump and electrification incentives. Those amounts and programs change by funding cycle, so we confirm what's currently offered before including it in any quote.
What Affects the Cost of Furnace Repair
We can't give an accurate price without seeing your furnace, because the same symptom can have very different causes. These are the main factors that shape the cost:
Whatever the repair, we explain the price before we start and won't do additional work without your approval.
- Which part failed: cleaning a flame sensor is a small job, while a control board, inducer motor, or blower motor is a bigger one
- Your furnace's brand, age, and model, which affect part availability
- Whether the furnace is single-stage, two-stage, or variable-speed
- Where it's installed: an attic, crawlspace, or tight closet takes more time than a garage
- Any secondary damage, such as a burned wire or overheated component
- Timing, since emergency visits outside regular hours involve after-hours scheduling
How a Furnace Repair Visit Works
When you contact us, we ask a few questions about what the furnace is doing, roughly how old it is, and where it's located. That helps the technician come prepared with the parts most likely to be needed. For no-heat situations, we offer 24/7 emergency service.
When the technician arrives, they talk with you about the symptoms, then inspect and test the system. You get a clear explanation of the problem and your options, with a price for each. If you approve, we make the repair, often in the same visit when the part is on hand.
Before leaving, we run the furnace through full heating cycles, check the safety controls and venting, and confirm warm air is reaching your registers. We'll also point out anything that may need attention later, such as a filter that's due for a change or wear we noticed, so you aren't caught off guard next winter.
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