Fast, Reliable Heating & Furnace Across Los Altos
Heating and furnace repair in Los Altos typically costs $150–$700 for repairs and $3,500–$7,500 for full replacement, with most service calls completed in a single trip. We’re Stonegate Heating & Air California, and we’ve spent 16 years building a reputation for owner-supervised HVAC work across Santa Clara County. Los Altos sits at the base of the Santa Cruz Mountains foothills, slightly warmer than cities directly on the Bay floor, with summer afternoons regularly climbing into the mid-to-upper 80s°F and occasionally spiking past 100°F during heat dome events. That climate reality, combined with a housing stock dominated by 1950s-to-1970s ranch homes on large, tree-canopied lots, creates furnace and ductwork challenges that generic contractors often misdiagnose. Call (855) 467-1888 for a free estimate. Jason Trent, our owner and Field Supervisor, oversees every Los Altos job personally.
Why Stonegate Heating & Air California Is Los Altos’s Preferred Heating & Furnace Company
Los Altos homeowners aren’t looking for a dispatcher in a call center. They’re looking for someone who knows that a furnace failure on a Loyola Drive acreage property means a longer service drive, a detached workshop that may have its own heating system, and ductwork that rodents have likely colonized. That’s exactly how we operate.
Our 499 verified reviews at a 4.7-star average reflect hundreds of real jobs across the Bay Area, including many in Los Altos and Los Altos Hills. Review volume matters because it proves repeatability. A handful of cherry-picked testimonials doesn’t show whether a contractor can handle the fourth emergency call of a Sunday evening. Sixteen years and nearly 500 reviews does.
Jason Trent doesn’t manage from a back office. He holds the title of Field Supervisor and is physically present on job sites. When we dispatch to a Los Altos property in the 94022, 94023, or 94024 ZIP codes, you’re getting experienced, owner-accountable hands on your system, not whichever technician happened to be available that day.
We also know the local terrain. The long, winding drives off Magdalena Avenue or along the Foothill Expressway corridor mean we stock our trucks for one-trip resolution. Nothing wastes a Los Altos homeowner’s Saturday like a tech who arrives, diagnoses, and discovers the part lives in a San Jose warehouse. We don’t do that.
Our Heating & Furnace Services in Los Altos
Furnace Repair
Furnace repair in Los Altos runs $150–$700 depending on the component and accessibility. The most common calls we get in this city involve failed ignitors, cracked heat exchangers in 30-year-old Carrier and Bryant units, and inducer motors that have burned out after years of cycling in dusty attic installations. On larger acreage properties, we also see detached workshop furnaces fail due to rodent nests in the ductwork. Those trees that make Los Altos beautiful also shelter squirrels and rats that chew flex duct and build nests directly over warm air returns. We serviced a ranch home on Loyola Drive where the original 1960s gas furnace in a detached workshop had a failed inducer motor on a weekend. Our tech arrived with a replacement motor for the Carrier unit, completed the repair in one trip, and also tightened the heavy-duty door springs the homeowner mentioned were sagging. One call. One trip. Done.
Furnace Replacement
A full furnace replacement in Los Altos costs $3,500–$7,500, but here’s what every contractor should tell you upfront: California Title 24 requires a duct-leakage test whenever HVAC equipment is replaced. The original 1960s flex and sheet-metal ductwork in these ranch homes routinely fails, often leaking 30–40% of airflow into unconditioned attic space. What starts as a straight equipment swap almost always triggers mandatory full duct replacement. We’ve had Los Altos homeowners call us for a second opinion after another contractor quoted a furnace swap, then returned with a change order that doubled the price. We build the full scope into our initial assessment. No surprises. The high property values here also mean frequent gut-renovations where we coordinate directly with general contractors on compressed timelines.
Furnace Tune-Up
A furnace tune-up in Los Altos costs $80–$200 and should happen annually, ideally before the first cold snap in late October or early November. Our tune-ups include combustion analysis, heat exchanger inspection for cracks, gas pressure verification, and filter assessment. Given Los Altos’s position in the wildfire-smoke transport zone, we also check whether your filtration system can handle MERV-13+ loads during fire season. Many original systems can’t. The tune-up is where we catch the small problems that become $700 repairs in January.
Heat Exchanger Inspection & Replacement
Cracked heat exchangers are a safety issue we don’t soft-pedal. A failed exchanger can leak carbon monoxide into your living space. In Los Altos’s aging housing stock, we find this most often in furnaces installed between 1985 and 2005 that have cycled through thousands of heating seasons. If we find a crack, we red-tag the unit and explain your options clearly. Replacement of the exchanger itself is sometimes possible; often, given the age of the surrounding system, full furnace replacement is the more cost-effective path. Jason Trent makes that call personally on every job he supervises.
Gas Valve Repair
Gas valve repair in Los Altos runs $150–$700. A failing gas valve can cause intermittent ignition, short cycling, or complete failure to fire. On properties with detached workshops and oversized doors, we see an additional failure mode: when heavy workshop doors are left open during heating season, the furnace’s draft inducer works harder to maintain proper combustion airflow, accelerating wear on the gas valve and related components. Our techs carry replacement gas valves for Carrier, Bryant, and American Standard units on every Los Altos truck.
Ignitor Replacement
Hot surface ignitors fail predictably after 3–5 years of use. In Los Altos, where many furnaces sit idle from May through October, the thermal cycling actually shortens ignitor life compared to climates with year-round heating demand. We stock ignitors for nine major brands and can usually replace one in under an hour.
What happens when you call
- 1
A real person answersNo phone trees — you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Los Altos
Whatever brand you have, we probably work on it. Stonegate’s technicians are factory-trained or deeply experienced on Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For Los Altos customers, that means no “we don’t service that brand” dead end. We stock common parts for Carrier, Bryant, and American Standard furnaces specifically, since those brands appear frequently in the local housing stock. If your detached workshop has a Daikin mini-split tied to a gas furnace backup, we handle both. From a single-room system to a full commercial setup, one team covers it.
Common Heating & Furnace Problems We See in Los Altos Homes
- Rodent-damaged ductwork on acreage properties. The large lots and mature tree canopy around Los Altos neighborhoods like South Los Altos and the area near Rancho San Antonio Preserve create ideal squirrel and rat habitat. These pests chew through flex duct and nest in warm attic spaces, blocking airflow and introducing contaminants. We find this almost exclusively in detached workshop systems and older ranch homes with original duct runs.
- Flame rollout from oversized workshop doors. When a heavy workshop door is left open during heating operation, the furnace struggles to maintain proper draft. The draft inducer motor overworks, combustion gases don’t vent correctly, and the system’s safety switches eventually trip. Homeowners often reset the switch repeatedly without addressing the root cause. We fix the furnace and explain the door protocol.
- Failed Title 24 duct-leakage tests triggering unexpected full replacements. Los Altos’s 1960s-era sheet-metal ductwork, with its original tape seals and uninsulated runs through hot attics, almost never meets modern leakage standards. Homeowners who expected a simple furnace swap find themselves facing a $3,500–$7,500 project that grew to include complete duct replacement. We identify this scope during our first visit.
- Wildfire-smoke filtration overload. Since 2017, Bay Area fire season has driven demand for whole-home air filtration upgrades. Original Los Altos furnaces and their undersized return ducts can’t handle MERV-13 filters without choking airflow and overheating the heat exchanger. We upgrade the return path or recommend standalone air purification systems that don’t compromise furnace operation.
Pricing for Heating & Furnace in Los Altos, CA
| Service | Price Range in Los Altos |
|---|---|
| Furnace Repair | $150–$700 |
| Furnace Replacement | $3,500–$7,500 |
| Gas Valve Repair | $150–$700 |
| Furnace Tune-Up | $80–$200 |
These ranges reflect what we’ve actually billed on Los Altos jobs over the past several years. The spread exists because a failed ignitor on an accessible attic furnace in a 1,400-square-foot ranch costs less than a full heat exchanger replacement in a cramped crawl space on a multi-addition home off Elena Road. Ductwork condition is the biggest variable we can’t predict until we inspect. California Title 24 compliance adds mandatory testing and potential replacement costs that many homeowners don’t anticipate. We provide upfront, itemized estimates before any work begins. Call (855) 467-1888 for a free, no-obligation assessment. Estimates are free. You’ll know the full scope before we start.
We Also Serve Cities Near Los Altos
Our service radius covers the full Santa Clara County corridor. We regularly dispatch to Los Altos Hills for estate properties with multiple detached structures, Mountain View for downtown commercial and residential mixed jobs, Stanford for faculty housing and university-adjacent properties, and Sunnyvale for the denser post-war housing stock near the Lawrence Expressway. If you need our full service area, visit our Heating & Furnace hub page. Same owner supervision, same 4.7-star standard, same one-trip commitment.
Serving Los Altos, CA — Our Local Coverage Area
We’re based in the Los Altos area and know this community well. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs — Heating & Furnace in Los Altos
Yes, we stock parts for common furnace brands and carry components for gas valve, ignitor, and inducer motor repairs specifically to handle detached workshop units in a single visit. Tell us your furnace brand and approximate age when you call, and we’ll confirm parts availability before dispatching. Call (855) 467-1888 with those details and we’ll schedule a same-week appointment.
Wildfire smoke forces you to run your HVAC system with windows sealed for days or weeks at a time, increasing runtime and filter loading. The original undersized return ducts in Los Altos ranch homes strain harder under continuous operation, and standard 1-inch filters clog quickly with fine particulate. We upgrade filtration systems and inspect return paths to handle extended smoke events without overworking your furnace.
Title 24 requires a duct-leakage test on any equipment replacement, and original 1960s ductwork in Los Altos almost always fails, typically leaking 30–40% of airflow. The test itself is mandatory; replacement becomes required if you fail. We test during our initial assessment and build the full scope into our estimate so you’re not surprised mid-project.
Yes, we repair gas valves on Lennox furnaces at properties throughout Los Altos, including acreage lots with long service drives. Our trucks carry replacement gas valves for all nine brands we service, Lennox included. We also check for the draft-related wear patterns common in workshop and outbuilding installations. Call (855) 467-1888 for an exact quote on your specific model.
Yes, heavy-duty workshop doors and their effect on furnace draft is a specific issue we address on Los Altos acreage properties. We repair the furnace, inspect the venting for proper draft under door-open conditions, and can recommend operational practices or hardware adjustments to reduce future strain. Our Loyola Drive job is a typical example: furnace repair plus door spring adjustment, one trip, done.
Ready to get your Los Altos furnace handled right? Call (855) 467-1888 for a free estimate. Jason Trent or one of our owner-supervised technicians will arrive with the parts, the experience, and the accountability to fix it in one trip.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving Los Altos and the greater Bay Area since 2008.