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.
La Mesa's cost story splits by elevation and era. Mount Helix estate homes run larger systems, 3 to 5 tons with multi-zone control, and cost more simply because of scale. Fletcher Hills and Grossmont's 1950s-70s tract homes need straightforward heat pump swaps but usually turn up original equipment sized 20 to 35 percent too large. Homes inside the La Mesa Village Historic Preservation District need Historic Preservation Commission sign-off on visible equipment, which permits through the City of La Mesa and adds review time rather than extra installed cost.
Central San Diego commercial work spans Mission Valley offices, Kearny Mesa light industrial, and college-area retail, and rooftop package unit replacement pricing sits at the county's top-line range since it covers everything from a service call to a full multi-unit swap.
| 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 La Mesa and Central 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.
Not usually more in installed dollars, but it adds time. Contributing structures inside the La Mesa Historic Preservation District need Historic Preservation Commission review on visible equipment changes, typically 4 to 8 weeks, and most projects route the line set through existing wall cavities and place the condenser off the street-facing side to avoid extra screening costs.
Central San Diego commercial work spans Mission Valley offices, Kearny Mesa light industrial, and college-area retail, and rooftop package unit replacement pricing sits at the county's top-line range since it covers everything from a service call to a full multi-unit swap.
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.