Held Heating and Air carries CSLB license #984892 under Casey William Held and serves residential San Diego properties from Suite R at 7075 Mission Gorge Road in Grantville, about a half mile north of Mission San Diego de Alcala in the 92120 ZIP. The C-20 classification covers warm-air heating, ventilating, and air-conditioning system fabrication, installation, maintenance, and repair for residential properties throughout the surrounding east communities. Interior finish work after an HVAC install — patching drywall around new register boots, repainting where supply lines penetrated walls — often falls to trades that follow the mechanical contractor, and Held coordinates scheduling with Wholesale Dealers Painting on jobs where wall or ceiling repair is part of the project scope. As a small-business operation, Held focuses on single-family and small multi-unit residential HVAC, handling furnace replacement, air conditioning installation, evaporator coil swaps, and thermostat upgrades without the overhead structure of a larger fleet operation. Furnace replacement work on Grantville's housing stock often involves 80-percent AFUE units being upgraded to 95-percent or higher two-stage gas furnaces with variable-speed blower motors, a swap that typically requires new flue venting from B-vent to PVC because the lower exhaust temperature of a condensing furnace cannot draft through a standard metal flue. The contractor bond is held at $15,000 with American Contractors Indemnity Company, and the license has been verified active through the CSLB's public records. Duct leakage testing on replacement systems uses a duct blaster pressurized to 25 Pascals, measuring total leakage in CFM25 against the California Title 24 threshold of six percent of nominal fan flow. Post-installation air quality is a concern in Grantville homes where construction dust from HVAC work settles into carpet fibers, and Held recommends running the new system's fan on continuous mode for 48 hours followed by a deep carpet cleaning from Finest San Diego Carpet Cleaning to clear particulate from the living space. Each replacement condenser is set on a composite pad leveled to within one-eighth inch of true and positioned with a minimum 24-inch service clearance on the disconnect side per NEC Article 440.