Commercial VAV Box Repair in Fontana — AC PRO-Compatible Service

Commercial Variable Air Volume (VAV) systems demand more than a quick fix. They require precise measurements, correct control strategies, and careful commissioning to meet design airflow, code requirements, and comfort expectations. #1 AC Guys provides engineering‑grade VAV box repair in Fontana with AC PRO‑compatible components and OEM parts, restoring balanced airflow, proper zoning, and dependable ventilation while lowering energy waste.

What we repair and calibrate

• Damper actuators (failed motors, seized linkages, end-stop misalignment)
• VAV controllers and terminal box boards (firmware, wiring, setpoints)
• Airflow sensors, thermistors, and pressure transducers (cleaning, replacement, recalibration)
• Reheat coils and valves (electric/gas/hydronic), staging and modulation issues
• Insulation, air leaks, and sound attenuation to reduce noise and losses
• Communication faults with BMS (BACnet/Modbus addressing, MS/TP health, grounding)

We also address persistent hot/cold complaints, poor ventilation, and short cycling by correcting control logic, minimum position, and reset strategies—then verify performance with measured data.

Our diagnostic process

1) System intake: review alarms, trend logs, and as‑builts.
2) Field testing: verify damper travel, k‑factors, and flow with calibrated instruments.
3) Controls check: confirm sensor accuracy, I/O mapping, PID tuning, and safeties.
4) Repair and replace: install AC PRO‑compatible parts and OEM components where required.
5) Air balance verification: adjust minimum/maximum cfm, pressure setpoints, and diversity.
6) Documentation and handoff: provide before/after data and recommendations for reliability.

Why #1 AC Guys for VAV box repair

• 80+ years of engineering experience; fourth‑generation family of engineers
• Factory‑trained by Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China)
• Proven success on large and complex commercial projects others turn down
• AC PRO‑compatible sourcing for rapid parts availability and consistent quality
• Licensed, bonded, insured, with clear pricing and documented results
• Mission‑driven: healthier indoor air and dependable comfort for occupants

AC PRO and your VAV system

We service a wide range of VAV terminal units using AC PRO‑compatible components and accessories, including actuators, controllers, sensors, and reheat parts. Our team ensures each replacement matches design intent, airflow requirements, and control sequence—so your zones receive the right cfm at the right time, without excess fan energy or overheating.

Building types we serve

• Office campuses and municipal buildings
• Retail, restaurants, and mixed‑use spaces
• Warehouses, logistics hubs, and light industrial
• Healthcare clinics and labs (non‑sterile areas)
• Schools, houses of worship, and community centers

Whether your facility is a single tenant suite or a multi‑story complex, our technicians coordinate with facility managers and GCs to minimize downtime and disruptions.

Code compliance, controls, and balancing

We align repairs with California Title 24, ASHRAE 62.1 ventilation guidance, and your building’s control sequences. From static pressure reset to supply air temperature and occupancy schedules, we correct the details that drive comfort and cost. After repairs, we verify cfm and control response under real load, then provide a punch list and balancing data.

Preventive maintenance for long‑term reliability

• Seasonal inspection and calibration of sensors and actuators
• Cleaning of airflow pickups and verification of k‑factors
• BMS trend review to catch drift before it becomes a complaint
• Valve exercise and reheat staging checks
• Filter and coil maintenance to protect IAQ and efficiency

Routine attention preserves comfort, improves indoor air quality, and prevents energy creep—critical for budgets and occupant satisfaction.

Service area and response

Based in Los Angeles, we serve Fontana and nearby communities along with Los Angeles County and adjacent areas, including Orange County, Ventura County, and Western Riverside County. We offer rapid dispatch, clear ETAs, and proactive status updates to keep your team informed.

Our difference: engineering first

As a fourth‑generation engineering family, we treat each VAV issue as a system problem to be solved—not a part to be swapped. We measure, test, and validate until airflow, temperature, and ventilation line up with design. That’s how we protect your energy spend and deliver healthier indoor air for the people who use your building every day.

Get a precise quote

Tell us about your VAV symptoms, BMS alarms, and recent work. We’ll provide a clear scope, timeline, and pricing—then back it with data after the repair. Schedule your commercial VAV box repair in Fontana today and experience the #1 AC Guys standard.