Fast, Reliable Heating & Furnace Across San Carlos
Heating repair in San Carlos typically runs $150–$700 for most furnace issues, and we can usually diagnose and fix the problem in a single visit. For full furnace replacement on acreage properties with detached workshops, expect $3,500–$7,500 depending on gas-line runs and access challenges.
We’re Redwood Heating & Air, and we’ve been driving the Peninsula’s back roads and long ranch driveways for 13 years. San Carlos isn’t just another stop on our route — it’s where we’ve replaced floor furnaces in mid-century ranches near Crestview, serviced Carrier units in workshop buildings off Alameda de las Pulgas, and run new gas lines through crawl spaces so tight you can’t turn around. Gregory Hahn founded this company and still leads every technical decision, which means when we pull up your gravel drive, the person diagnosing your system has a Master Technician designation and 13 years of field experience across nine major brands. Call us at (844) 875-9451.
Why Redwood Heating & Air San Diego Is San Carlos’s Preferred Heating & Furnace Company
San Carlos homeowners have left us 428+ verified reviews averaging 4.6 stars, and a noticeable chunk of those come from the acreage properties west of El Camino Real where other companies won’t make the trip. We’ve earned that trust by showing up once with the right parts, not sending a junior tech who has to “check with the office” about a 40-year-old Carrier or a heavy-duty workshop door.
Our response time to San Carlos is same-day or next-day for standard calls, and we prioritize emergency heat-outs during fall Diablo wind events when temperatures spike into the mid-90s and homeowners discover their heating-only systems can’t cope. We know the difference between a flatland ranch near Brittan Avenue with a 16-inch crawl space and a hillside property off Melendy Drive with slab-on-grade foundations and no duct access at all. That local knowledge changes what we pack in the truck.
Gregory Hahn holds a Master Technician designation — the company’s top credential is on the truck, not in a corporate office. When you call (844) 875-9451, you’re talking to a team where the founder still reviews complex jobs personally.
Our Heating & Furnace Services in San Carlos
Furnace Repair
Most San Carlos furnace repair calls we get are for ignitor failures, gas valve issues, or blower motors that finally quit after 30+ years of service. On acreage properties, we also see a distinct pattern: the furnace in the main house runs fine, but the detached workshop heater — often a smaller unit exposed to more temperature swings — fails first. We stock ignitors, flame sensors, and gas valves for Carrier, Lennox, Bryant, and American Standard units common in Peninsula homes, and we carry heavy-duty springs and hardware for oversized workshop doors that need to come off for equipment access. A typical furnace repair in San Carlos runs $150–$700.

Furnace Replacement
Replacement is where San Carlos’s housing stock gets interesting. The original 1960s forced-air gas furnace is often still running, but the galvanized sheet-metal ductwork snaking through a 16-inch crawl space is so leaky and undersized that adding an AC coil would push static pressure beyond what the blower can handle. We see this constantly in the flatlands between El Camino Real and the Bayshore. What starts as a “just add AC” quote becomes a full duct-remediation or ductless proposal. On rural properties, we also factor in longer gas-line runs and whether we need to coordinate with heavy-duty door work to get equipment into detached workshops. Furnace replacement in San Carlos typically ranges from $3,500 to $7,500.

Heat Exchanger Inspection and Replacement
Cracked heat exchangers are a safety issue we don’t negotiate on. In San Carlos’s older housing stock — those 1945–1975 ranches built during the postwar Peninsula boom — we’ve found heat exchangers failing not from age alone but from years of over-firing due to dirty burners and neglected maintenance. The marine layer here keeps humidity high enough that corrosion sets in faster than you’d expect in a “mild” climate. We inspect with cameras, explain exactly what we see, and replace with OEM-spec exchangers when needed. If your carbon monoxide detector has chirped or your furnace smells wrong, shut it off and call us.

Gas Valve Repair
Gas valves on older furnaces — especially the standing-pilot units still found in some San Carlos workshop buildings — can stick, leak, or fail to open fully after decades of service. We don’t clean and hope; we test manifold pressure with digital gauges and replace with factory-spec valves rated for your exact model. On rural properties with long supply lines from the main house, we also check for pressure drop issues that can mimic valve failure. This is precise work, and it’s where Gregory Hahn’s Master Technician background shows in the diagnosis.

What happens when you call
- 1
A real person answersNo phone trees — you reach a local pro.
- 2
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 San Carlos
We service your brand — whether it’s the Carrier furnace in your Crestview ranch, the Lennox unit heating your workshop off Edgewood Road, or the Bryant system in a Redwood Shores client’s guest house. Our factory training and field experience cover nine major HVAC brands: Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For San Carlos customers, this means we don’t need to “order parts and come back next week.” Our trucks carry the most common ignitors, gas valves, flame sensors, and blower motors for these brands, and our relationships with Peninsula suppliers get us same-day or next-day delivery on anything else. Daikin and Bryant parts move fast here — we keep them in rotation.
Common Heating & Furnace Problems We See in San Carlos Homes
- Original 1960s gas furnace runs, but ductwork can’t handle any load increase. The galvanized sheet-metal supply runs in those shallow crawl spaces were sized only for heating. We’ve had homeowners ask us to “just add AC” and had to explain why the blower would burn out trying to push through undersized, leaky ducts. Ductless mini-splits or full duct remediation are usually the honest answer.
- Oversized workshop doors with heavy springs fail, blocking equipment access. On acreage properties, that detached workshop with the 10-foot roll-up door is where your backup heater, tools, and sometimes the replacement furnace itself are stored. When the torsion springs go, you’re not just cold — you’re locked out. We coordinate heavy-duty spring replacement with our heating work so the job finishes in one trip.
- Long service drives make multi-trip repairs impractical. A missed part on a rural San Carlos property can delay the job for days, not hours. We pre-diagnose aggressively by phone, verify model numbers, and pack for contingencies. It’s why our acreage customers specifically mention “one trip” in their reviews.
- Fall Diablo wind events expose the cooling gap. San Carlos sits in a transitional zone — mild most of the year, but when those offshore winds hit in September or October, temperatures spike into the mid-90s and homes with heating-only systems are caught flat-footed. We get emergency calls from homeowners who’ve ignored cooling for decades and now need immediate relief.
Pricing for Heating & Furnace in San Carlos, CA
We’re upfront about numbers because San Carlos homeowners research before they call. Here’s what we see in this market:
| Service | Typical Range in San Carlos |
|---|---|
| Furnace Repair | $150 – $700 |
| Furnace Replacement | $3,500 – $7,500 |
| Furnace Tune-Up | $80 – $200 |
What moves you within these ranges? Access is the big one for San Carlos. A standard flatland ranch near El Camino Real with good crawl space clearance? Straightforward. A hillside property with slab foundation, or a rural acreage requiring a 200-foot gas-line extension to a detached workshop? That adds material and labor. Heavy-duty door work for equipment access adds time too. We give firm quotes after inspection — never ballpark guesses that balloon later. Estimates are free. Call (844) 875-9451 to schedule.
We Also Serve Cities Near San Carlos
Our Heating & Furnace team covers the full Peninsula corridor. We regularly work in Belmont’s hillside homes, Redwood Shores’ waterfront properties, Redwood City’s diverse housing stock from downtown Victorians to new construction, and North Fair Oaks’ unincorporated neighborhoods with their own access challenges. Same standards, same Master Technician oversight, same phone number: (844) 875-9451.
Serving San Carlos, CA — Our Local Coverage Area
We’re based in the San Carlos 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 San Carlos
Yes — we specialize in these jobs, and they’re more common in San Carlos than most Peninsula cities. We drove up to a rancher’s property near the Crestview neighborhood last winter to find a 40-year-old Carrier furnace in a detached workshop that had finally failed. The homeowner had already sourced a replacement Lennox unit, but the job required our crew to run new gas line through a long crawl space and install heavier-duty springs on the workshop’s oversized door to accommodate the equipment. We swapped the ignitor, sealed the ductwork, and had the heat back in a single trip. Call (844) 875-9451 to discuss your setup.
The original galvanized ductwork was sized only for heating loads, and 16-inch crawl spaces make retrofitting difficult. We often recommend ductless mini-splits or full duct remediation instead. San Carlos’s postwar ranch homes were built fast with minimal duct clearance and supply runs that can’t handle the extra static pressure of an AC coil. We’ve tested enough systems to know when a blower is already at its limit. If you’re set on central cooling, we’ll quote honest ductwork replacement — not a setup that fails in July. Call for a free assessment: (844) 875-9451.
Installation typically ranges from $3,500 to $7,500, but longer gas-line runs or heavy-duty door work may increase the price. We give a firm quote after inspecting the site. Rural properties add variables: distance from main gas service, whether the workshop needs its own meter upgrade, and access for equipment. We price these jobs in person, not over the phone, because guessing wrong means a second trip — and on a long San Carlos driveway, nobody wants that. Schedule your free estimate at (844) 875-9451.
Yes, during fall Diablo winds, temperatures can spike into the mid-90s, and homes with only heating find their systems useless. We recommend servicing the furnace now and considering a heat pump or mini-split for backup cooling. The marine layer keeps most summer days comfortable, but those offshore wind events are getting more frequent and intense. A heat pump gives you efficient heating plus cooling for the two dozen days a year you suddenly need it. Ask us about dual-fuel or all-electric options when you call (844) 875-9451.
We work on Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, and Bryant — common brands in Peninsula homes. Our techs carry parts for most models. These eight brands cover probably 90% of what we see in San Carlos, from the Carrier units in 1970s ranches to the Daikin systems in newer infill construction. If you’ve got something else — a Nordyne, a Comfortmaker, a relic from a defunct manufacturer — we can still source parts, but it may take an extra day. Call (844) 875-9451 with your model number and we’ll tell you straight.
Ready to get your San Carlos home or workshop heating properly? Whether it’s a failed ignitor in a 1960s ranch, a full replacement on an acreage property, or an honest assessment of whether your ductwork can handle more load, Gregory Hahn and our team will give you a Master Technician’s diagnosis — not a sales pitch. Call (844) 875-9451 for a free estimate.
Written by Gregory Hahn, Owner at Redwood Heating & Air, serving San Carlos since 2012.