When your furnace fails on a cold San Jose night, the cause is usually something specific and fixable: a dirty flame sensor, a worn ignitor, a failed blower motor, a bad pressure switch or a thermostat problem.
We find the cause, explain it, and give you the price before any repair begins. Emergency heating service is available 24/7.
Most San Jose furnace repairs run about $300 to $650, with major repairs such as a heat exchanger or gas valve running $1,100 to $2,400. A diagnostic service call is typically $99 to $149.
Simple fixes like cleaning a flame sensor come in lower. The full breakdown is in our furnace repair pricing guide.
Some furnace problems are not about comfort. Turn the furnace off and get help right away if any of these happen:
Keep a working carbon monoxide detector on every level and near bedrooms, and replace the batteries each fall. The CPSC carbon monoxide guide explains what to do.
The most common cause is a dirty flame sensor, which stops detecting the flame and shuts the furnace down as a safety measure. Cleaning it usually takes about 20 minutes. A worn ignitor is the next suspect.
Could be thermostat settings, a tripped limit switch, a failed ignitor or a gas valve problem. This is a diagnostic first call.
The furnace turns on and off every few minutes. Usually a dirty filter, closed or blocked registers, or a failing control board.
A failed capacitor, which is the cheaper fix, or a failed blower motor, which is the bigger one.
A loose blower wheel, failing bearings or duct expansion. Do not ignore a new noise.
Dust burning off the heat exchanger is normal for the first run. A smell that keeps going is not, and needs a technician.
| Repair | Typical cost |
|---|---|
| Service call (San Jose) | $99 to $149 |
| Average common repair (San Jose) | $300 to $650 |
| Average major repair (San Jose) | $1,100 to $2,400 |
| Flame sensor cleaning | $120 to $220 |
| Ignitor replacement | $220 to $450 |
| Pressure switch replacement | $210 to $420 |
| Blower motor replacement | $550 to $1,100 |
| Draft inducer motor | $450 to $950 |
| Gas valve replacement | $500 to $1,100 |
| Control board replacement | $450 to $950 |
| Heat exchanger replacement | $1,200 to $2,400 |
These are typical ranges across our service areas. Furnace calls in San Jose run from late October through March. A fall tune up before the first cold snap catches the sensor and ignitor problems that cause most no heat calls.
Replacement is worth pricing when several of these are true:
In the Bay Area there is another factor. The Bay Area Air District's rule for new gas furnaces starts January 1, 2029, and the products that meet it are electric, such as heat pumps.
A working furnace can stay, but if yours is near the end of its life, it is worth knowing what the replacement options will look like. See furnace installation in San Jose and heat pump installation in San Jose.
You can safely change the filter, check the thermostat batteries and settings, and keep the area around the furnace clear. Do not open the burner area, adjust gas valves, remove safety switches or try to bypass any control.
Those parts handle gas and combustion, and mistakes can be dangerous. If a safety switch keeps tripping, there is a reason, and the fix is to find it, not to jump the switch.
We serve homes across San Jose, including Willow Glen, Almaden Valley, Rose Garden, Naglee Park, Hanchett Park, Silver Creek Valley, Cambrian Park, Evergreen, Berryessa and the Santana Row area. Our office is at 226 Airport Pkwy Ste 622, San Jose, CA 95110.
See HVAC in San Jose for permits and rebates.
We repair and install all major brands. Each brand page lists the models we install, the problems we see most and what the warranty typically covers. See how we match a technician to your brand.
Most repairs run about $300 to $650. Major repairs such as a heat exchanger or gas valve run $1,100 to $2,400. The diagnostic call is typically $99 to $149.
Common causes are thermostat settings, a failed ignitor, a tripped limit switch or a gas valve problem. If it keeps happening, call us. This needs a diagnosis.
Short cycling usually comes from a dirty filter, blocked registers or a failing control board. Replace the filter first. If it continues, call.
A dusty smell for the first run of the season is normal. A smell that keeps going, or smells like gas or burning plastic, is not. Turn the furnace off and call.
Not automatically. If it works and has no safety problems, a repair may be fine. If it needs repeated repairs or has a cracked heat exchanger, replacement makes sense. We give you both prices.
Often, yes. A heat pump heats and cools from one system. We check your electrical panel and ducts first. See heat pump installation in San Jose.
Yes, 24/7.
Yes. See brands we service.
Call any hour for emergency service, or reach us during business hours for a visit or a quote.
