Fast, Reliable Heating & Furnace Across San Lorenzo
Heating and furnace repair in San Lorenzo typically costs $150–$700 for repairs, $3,500–$7,500 for full replacement, and most calls are completed same day. Stonegate Heating & Air California has served San Lorenzo and the unincorporated Alameda County area for 16 years, with owner Jason Trent supervising every job personally. Call (855) 467-1888 for a free estimate.
San Lorenzo’s roughly 8,500 Bohannon-built homes were designed without ductwork or forced-air systems, so converting from original floor furnaces to modern gas furnaces requires retrofitting ducts into slab or shallow crawl spaces — a challenge almost nonexistent in adjacent Hayward or San Leandro. We’ve spent years developing methods for these specific homes. Jason Trent, our Field Supervisor, has walked hundreds of San Lorenzo crawl spaces on streets from Via Alamitos to Hesperian Boulevard, and our technicians know the exact clearance issues and moisture patterns these houses present.
Why Stonegate Heating & Air California Is San Lorenzo’s Preferred Heating & Furnace Company
Our reputation in San Lorenzo is built on jobs completed, not promises made. We’ve earned 499 verified customer reviews averaging 4.7 stars across platforms — a volume that reflects consistent, repeatable results across hundreds of real jobs, not a handful of cherry-picked testimonials. Many of those reviews come from San Lorenzo homeowners who found us after other contractors declined their floor-furnace conversion or quoted ductwork plans that ignored the realities of a 1948 slab foundation.
Response time matters when your only heat source is a 70-year-old cast-iron unit in January. We’re positioned to reach San Lorenzo quickly from our Sacramento base, and we prioritize no-heat calls in the 94580 zip code during cold snaps. Jason Trent serves as active Field Supervisor, not a passive figurehead — meaning company leadership is physically present on job sites, not managing from a back office.
Our local knowledge runs deep. We know that pulling a permit for furnace replacement in San Lorenzo’s unincorporated zone triggers Alameda County Title 24 compliance requirements that catch homeowners off guard. We handle that paperwork. We also know that Bay shoreline dampness accelerates corrosion in crawl-space equipment, so we spec corrosion-resistant components and seal duct joints against moisture intrusion as standard practice.
Our Heating & Furnace Services in San Lorenzo
Furnace Repair
Furnace repair in San Lorenzo runs $150–$700 depending on the component and accessibility. We fix gas valves, ignitors, blower motors, and control boards on all major brands. Many San Lorenzo calls involve original floor furnaces that have finally rusted through from decades of bay dampness in crawl spaces — we assess whether repair is cost-effective or if replacement makes more sense given Title 24 requirements.
Furnace Replacement
Full furnace replacement in San Lorenzo ranges from $3,500–$7,500, with Bohannon-era conversions typically falling in the upper half due to ductwork retrofitting. We recently replaced a 1952 floor furnace on Via Alamitos, where the original unit was still nestled in the hallway. We installed a 96% AFUE Carrier gas furnace and ran new flex duct through the shallow crawl space, sealing all joints against the bay dampness — turning that hallway heater into whole-home comfort. Every replacement we do in San Lorenzo includes load calculation, Title 24 compliance documentation, and permit coordination with Alameda County.
Furnace Tune-Up
Annual furnace tune-ups in San Lorenzo cost $80–$200 and are essential for these aging systems. For original floor furnaces still in service, we check heat exchanger integrity, gas valve operation, and venting safety — corrosion from persistent dampness is the primary failure mode we catch early. For newer retrofitted systems, we focus on duct leakage, filter condition, and condensate drainage. The mild but damp conditions here make crawl-space moisture management a regular part of any maintenance visit.
Heat Exchanger Inspection & Replacement
Cracked heat exchangers are a safety issue we take seriously, especially in San Lorenzo’s older units that have cycled through 70+ winters. We perform combustion analysis and visual inspection, and if replacement is needed, we coordinate with Alameda County for proper permitting. Given the confined plenum space in many Bohannon homes, heat exchanger work often requires creative access solutions — something our Heating & Furnace team has developed specific techniques for.
Ignitor Replacement & Gas Valve Repair
These are the most common no-heat calls we get from San Lorenzo in fall and winter. Hot surface ignitors fail predictably after 3–5 years; gas valves can stick from corrosion or debris. We stock replacement ignitors and gas valves for Carrier, Trane, Lennox, and other major brands, so most San Lorenzo residents have heat restored in a single visit.
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 Lorenzo
We’re certified to work on nine leading HVAC brands — Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard — eliminating the “we don’t service that brand” dead end homeowners often hit. For San Lorenzo customers, this means whatever furnace you have, whatever furnace you’re considering, we can service it, source parts for it, and warranty our work on it. We maintain relationships with regional distributors to get common repair parts quickly, and for full replacements, we spec equipment specifically for the damp crawl-space conditions these homes present.
Common Heating & Furnace Problems We See in San Lorenzo Homes
- Original floor furnaces rust out from bay dampness in crawl spaces. These cast-iron units were never designed for decades of marine-layer moisture. We find corrosion holes in heat exchangers, deteriorated gas valves, and compromised venting — all safety hazards that require immediate attention.
- Under-insulated slab edges cause cold floors and heat loss in living areas. Bohannon homes on slab foundations lose significant heat through the perimeter. When we retrofit ducted systems, we often recommend addressing slab-edge insulation as part of the project — otherwise you’re heating the soil.
- Builder-grade ductwork in Bohannon-era retrofits leaks at connections, wasting fuel. Previous contractors sometimes rushed duct installations in these tight crawl spaces. We find disconnected flex runs, unsealed junctions, and improper support that lets ducts sag and pool condensation.
- Title 24 compliance gaps in unpermitted past work. Alameda County enforces California’s energy code strictly. We’ve encountered multiple San Lorenzo homes where a previous furnace replacement was done without proper permits or compliance documentation, creating problems at resale or insurance claim time.
Pricing for Heating & Furnace in San Lorenzo, CA
| Service | Price Range in San Lorenzo |
|---|---|
| Furnace Repair | $150–$700 |
| Furnace Replacement | $3,500–$7,500 |
| Furnace Tune-Up | $80–$200 |
What drives cost within these ranges? Accessibility is the big variable for San Lorenzo’s Bohannon homes. A furnace replacement with existing ductwork and a generous equipment closet falls at the lower end. Converting from a hallway floor furnace with no ductwork, running new flex through a shallow damp crawl space, and coordinating Alameda County permits — that’s upper-range work, and it’s work we’ve done dozens of times. We provide written, itemized estimates before any work begins. Call (855) 467-1888 for yours; estimates are free.
We Also Serve Cities Near San Lorenzo
Our service area extends throughout the East Bay and beyond, including Ashland, San Leandro, Cherryland, and Castro Valley. Each community has its own housing stock and climate considerations — San Leandro’s hills, Castro Valley’s larger lots, Ashland’s mix of eras — but the same owner-supervised service standard applies. If you’re on the border between San Lorenzo and a neighboring community, call us and we’ll confirm coverage.
Serving San Lorenzo, CA — Our Local Coverage Area
We’re based in the San Lorenzo 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 Lorenzo
No — a central gas furnace requires ductwork to distribute heated air, and your Bohannon-era home was built without it. The conversion means running supply and return ducts through your crawl space or attic, which is the primary challenge and cost driver in San Lorenzo replacements. We design these retrofits specifically for the tight clearances and moisture conditions these homes present. Call (855) 467-1888 to discuss your specific layout.
Yes — San Lorenzo is unincorporated Alameda County, and any furnace replacement requires a county permit plus Title 24 energy compliance documentation. This catches many homeowners off guard, especially if a previous replacement was done without permits. We pull permits and handle compliance paperwork as standard on every San Lorenzo replacement. Call (855) 467-1888 and we’ll walk you through what’s required for your property.
Because that’s exactly what it was designed to do. These original units were centered in narrow hallways as the sole heat source for the whole house, relying on convection and door openings to reach other rooms. It’s inefficient and uneven, which is why most San Lorenzo homeowners eventually convert to ducted systems or ductless mini-splits for proper whole-home comfort. Call (855) 467-1888 to explore your upgrade options.
We regularly install Carrier and Trane equipment in San Lorenzo for their corrosion-resistant heat exchangers and reliable condensate management, though Lennox and other brands we service also perform well with proper installation. The critical factor isn’t the brand name — it’s proper sizing, sealed ductwork, and moisture protection in the installation. Our Field Supervisor, Jason Trent, specs each job for the actual conditions we find in your crawl space. Call (855) 467-1888 for a specific recommendation.
Once yearly, ideally in early fall before heating season begins. For original floor furnaces still running, annual inspection is essential for safety — we check heat exchanger integrity, gas valve operation, and venting condition. For newer systems, annual maintenance preserves efficiency and catches issues before they become no-heat emergencies. Call (855) 467-1888 to schedule; tune-ups run $80–$200.
Ready to get your San Lorenzo home heating properly? Whether you need a floor furnace converted, a rusted heat exchanger replaced, or just a thorough tune-up before winter, Stonegate Heating & Air California has the specific experience these homes demand. Owner Jason Trent supervises every project personally. Call (855) 467-1888 for a free, written estimate — no pressure, no surprises, just straight answers about your heating system.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving San Lorenzo and the greater Sacramento region since 2008.