Last updated: April 23, 2026
Commercial HVAC service in San Diego County ranges from a $149 service call to a $25,000 rooftop unit replacement on a larger building. Most repair calls land well under $2,500. A full RTU replacement is the big-ticket item, priced by tonnage, and maintenance contracts are priced by square footage rather than a flat rate.
Granite Hills is El Cajon-adjacent foothill terrain with custom ranch and equestrian properties on larger lots, many running 1960s-80s systems at true end of life. Extreme East County summer heat, 100 to 110 degrees common, and SDG&E high-risk fire zone designation both push toward premium variable-speed equipment and growing battery-backup interest. Permits route through the County of San Diego since Granite Hills is unincorporated.
East County commercial HVAC carries the highest summer cooling loads in the county, and equipment sized for that load costs more on a full rooftop replacement. Maintenance contracts here focus on predictable monthly cost specifically to avoid an emergency repair during a heat event.
| Item | Typical cost | Notes |
|---|---|---|
| Commercial service visit | From $149 | Diagnostic and minor repair on rooftop or packaged units |
| Rooftop unit (RTU) repair | $400 - $2,500 | Most common repair range, covers motors, boards, and refrigerant work |
| RTU replacement, 3 to 5 ton | $8,000 - $18,000 | Typical for a small retail space or office suite |
| RTU replacement, 7.5 to 10 ton | $15,000 - $25,000 | Typical for a larger retail, restaurant, or warehouse space |
| Preventive maintenance contract | Priced by square footage | Quoted per building, not a flat per-unit rate |
| After-hours or weekend service call | Standard rate | Scheduled around your business hours, no separate overtime surcharge |
Ranges reflect Granite Hills and East County San Diego. Your exact figure depends on the factors below. We quote flat-rate before starting.
A preventive maintenance contract catches most rooftop unit failures before they turn into an emergency call during business hours, and it's priced by square footage so a small suite doesn't pay the same rate as a large warehouse. SDG&E offers commercial rebate programs for high-efficiency RTU replacements, and those figures depend on tonnage and efficiency tier, so we confirm the real number for your building rather than quoting one up front.
For a custom ranch-style home on a larger Granite Hills lot, expect $14,000 to $26,000 for a variable-speed heat pump replacement, more if outbuildings or a barn office need separate equipment. Larger parcels here often mean longer refrigerant line-set runs from house to condenser pad than a standard suburban lot, which adds modestly to labor cost.
East County commercial HVAC carries the highest summer cooling loads in the county, and equipment sized for that load costs more on a full rooftop replacement. Maintenance contracts here focus on predictable monthly cost specifically to avoid an emergency repair during a heat event.
A service call starts at $149. Most repairs run $400 to $2,500. A full rooftop unit replacement runs $8,000 to $25,000 depending on tonnage, with larger buildings needing multiple units.
Yes, for most property owners and businesses. A maintenance contract is priced by square footage and catches problems during a scheduled visit instead of an emergency call that disrupts business hours.
A standard service visit at $149 covers diagnostics and minor adjustments. Most straightforward repairs, like a failed contactor or a refrigerant top-off, stay under $1,000.
A full rooftop unit replacement is the largest expense, running $8,000 to $25,000 depending on tonnage. Buildings with multiple RTUs sometimes replace them in phases to spread out the cost.
Flat-rate pricing, confirmed before any work starts. Same-day scheduling on most calls.