Fast, Reliable Heating & Furnace Across San Anselmo
Heating and furnace service in San Anselmo runs $150–$700 for most repairs, $80–$200 for tune-ups, and $3,500–$7,500 for full replacements. We’re usually on-site in San Anselmo within the same day you call. Our Heating & Furnace team knows the Ross Valley’s thermal pocket well — we’ve spent 16 years retrofitting modern HVAC into the pre-1950 Craftsman bungalows and Victorians that dominate this town’s hillsides and creek corridors. Call (855) 467-1888 for a free estimate.
Why Stonegate Heating & Air California Is San Anselmo’s Preferred Heating & Furnace Company
We’ve built our reputation in San Anselmo one job at a time. Owner Jason Trent serves as active Field Supervisor on projects here, not a back-office figurehead. That means the person signing off on your furnace replacement is the same person who crawled through your neighbor’s crawlspace last month.
Sixteen years and nearly 500 verified reviews at a 4.7-star average tell the story better than we can. San Anselmo homeowners specifically mention our willingness to solve problems that other contractors walk away from — gravity wall heaters in 1920s bungalows, ductless retrofits in homes with no existing infrastructure, floodproofing equipment near San Anselmo Creek. We don’t send whichever tech is available. Jason supervises every project.
Our response time to San Anselmo is typically same-day for standard calls, because we keep common parts for Carrier, Trane, Lennox, and other major brands stocked for Marin County routes. We know the difference between a hillside home on San Anselmo Avenue and a creek-adjacent property on Center Boulevard, and we plan accordingly.
Our Heating & Furnace Services in San Anselmo
Furnace Repair
Furnace repair in San Anselmo often means dealing with equipment that shouldn’t still be running. Original floor furnaces and gravity wall heaters in homes built between 1900 and 1950 develop cracked heat exchangers from decades of thermal cycling. Salt air from the coast accelerates corrosion on burner assemblies and gas valves in pier-and-beam crawlspaces. A typical furnace repair in San Anselmo runs $150–$700, depending on whether we’re replacing a ignitor or addressing deeper combustion chamber damage. We diagnose before we quote.
Furnace Replacement
Replacing a furnace in San Anselmo is rarely a simple swap. Most homes here lack central ductwork entirely. We replaced an original gravity wall heater in a 1920s Craftsman bungalow on San Anselmo Avenue with a high-efficiency Carrier gas furnace, running new ductwork through the cramped crawlspace and upgrading the electrical panel to handle a future AC unit, all while floodproofing the equipment against potential creek overflow from nearby San Anselmo Creek. Furnace replacement in San Anselmo typically costs $3,500–$7,500. The variance comes from ductwork fabrication, electrical upgrades, and whether we need to engineer around a shallow crawlspace or flood-prone location.
Furnace Tune-Up
San Anselmo’s damp valley winters and salt-laden air make annual furnace tune-ups more than maintenance — they’re prevention. We inspect heat exchanger fins for coastal corrosion, test gas valve operation after months of moisture exposure in low crawlspaces, and verify that pilot assemblies haven’t degraded from the thermal cycling common in older equipment. A furnace tune-up in San Anselmo costs $80–$200. We recommend scheduling before the valley’s cold-air inversions start in late October.
Heat Exchanger Inspection & Replacement
Cracked heat exchangers are the most serious safety issue we encounter in San Anselmo’s aging housing stock. Gravity wall heaters and early floor furnaces crack after decades of expansion and contraction. The Ross Valley’s temperature swings — hot days, cold nights — accelerate metal fatigue. Salt air corrosion weakens seams further. Heat exchanger work in San Anselmo runs $150–$700. If the unit is original to a pre-1950 home, we often recommend full replacement rather than band-aid repairs, and we’ll show you exactly why.
What happens when you call
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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 San Anselmo
Whatever brand you have, we service it. Our technicians are factory-trained or experienced on nine leading HVAC brands: Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. We stock common parts for Carrier, Trane, and Lennox on our Marin County routes, which means faster turnaround for San Anselmo customers. No “we don’t service that brand” dead ends. From a single-room mini split to a full commercial system, one team handles it.
Common Heating & Furnace Problems We See in San Anselmo Homes
- Salt-air corrosion on heat exchanger fins and burner assemblies. Homes within a few miles of the bay, particularly those on the western edge of San Anselmo toward Fairfax, see accelerated corrosion on uncoated metal. We inspect for this specifically during tune-ups and specify coated or stainless components for replacements.
- Cracked heat exchangers in original gravity wall heaters. These units from the 1920s–1940s have cycled through thousands of heating seasons. The Ross Valley’s sharp day-night temperature swings stress metal beyond its design life. Replacement is usually the only safe option.
- Rusted gas valves and pilot assemblies in low crawlspaces. San Anselmo’s pier-and-beam foundations trap moisture. Furnaces installed in these spaces develop corrosion on critical safety components. We elevate equipment and specify waterproofing where possible.
- Undersized electrical panels blocking modern furnace or heat pump installation. Pre-1950 homes throughout the 94960 and 94979 ZIP codes often have 60-amp service. Upgrading to a high-efficiency furnace with variable-speed blower, or adding any cooling capacity, requires panel work. We coordinate this as part of the project, not as a surprise add-on.
Pricing for Heating & Furnace in San Anselmo, CA
| Service | Typical Range in San Anselmo |
|---|---|
| Furnace Repair | $150–$700 |
| Furnace Replacement | $3,500–$7,500 |
| Furnace Tune-Up | $80–$200 |
| Heat Exchanger Work | $150–$700 |
What moves a San Anselmo job toward the higher end: extensive ductwork fabrication for homes with no existing system, electrical panel upgrades, floodproofing measures for creek-adjacent properties, and access challenges in shallow crawlspaces. What keeps costs down: straightforward component swaps on accessible equipment, no structural modifications needed. We quote upfront after inspection, not after starting work. Estimates are free. Call (855) 467-1888.
We Also Serve Cities Near San Anselmo
Our Marin County coverage extends to Fairfax, Kentfield, San Rafael, and Larkspur. Same owner-supervised service, same multi-brand expertise, same day response when scheduling allows. Whether you’re in the Ross Valley thermal pocket or closer to the bay, the same team handles your Heating & Furnace needs.
Serving San Anselmo, CA — Our Local Coverage Area
We’re based in the San Anselmo 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 Anselmo
Yes, we regularly convert floor furnaces and gravity wall heaters to forced-air systems in San Anselmo’s pre-1950 homes. The process involves fabricating compact ductwork for shallow crawlspaces and often upgrading the electrical panel, but we avoid structural modifications. Most projects take two to three days. Call (855) 467-1888 for an exact quote — estimates are free.
If your furnace is in a crawlspace or ground-level utility room near the creek corridor, yes, floodproofing is essential. The 2005 flood event damaged multiple HVAC systems in this zone. We elevate equipment on sealed platforms, specify waterproof enclosures, and design intake/exhaust routing to avoid water intrusion. This is a routine design conversation for us that hillside Marin contractors rarely encounter. Call (855) 467-1888 to assess your specific flood risk.
Salt air accelerates corrosion on uncoated heat exchanger fins, burner assemblies, and fasteners by several years compared to inland locations. We see this most in homes west of the downtown corridor toward Fairfax. Our response is specifying coated or stainless components during replacement, and inspecting for early corrosion during annual tune-ups. Regular maintenance extends service life significantly in this environment. Call (855) 467-1888 to schedule a corrosion assessment.
Yes, this is our most common project type in San Anselmo. We design compact duct systems for homes with no existing infrastructure, and we coordinate electrical panel upgrades as part of the installation. The Ross Valley’s genuine cooling load — 10–15°F hotter than coastal Marin in summer — makes heat pumps increasingly practical here despite the retrofit complexity. Most San Anselmo homeowners in this situation choose a high-efficiency gas furnace with future AC prep. Call (855) 467-1888 to discuss your specific layout.
Persistent pilot failure in San Anselmo usually traces to moisture intrusion in low crawlspaces, corrosion on the thermocouple or gas valve from salt air exposure, or draft issues in aging venting systems. The damp valley floor holds cold air overnight, creating condensation conditions that affect combustion components. We diagnose the root cause rather than repeatedly relighting the pilot. Most repairs run $150–$400. Call (855) 467-1888 for same-day service.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving San Anselmo and the Ross Valley since 2008.