Commercial Rooftop Unit Inspection & Testing in Southern California and Arizona

What is a rooftop unit inspection and testing visit?

A rooftop unit inspection and testing visit is aimed at the cause of a problem rather than its latest symptom. The technician inspects the unit and tests its electrical, refrigerant, airflow, and controls sides, ideally while it runs under real load.

We inspect and test rooftop packaged units up to 100 tons, all makes and models, including equipment someone else installed. The usual trigger is a unit that keeps producing work orders when nobody has found out why.

Which work orders call for a full inspection and test?

Book a full inspection and test when a unit generates repeat calls for the same complaint, when faults clear before anyone reaches the roof, or when a site uses noticeably more energy than similar sites in the portfolio.

• Three or more work orders on one unit for the same complaint.
• Lockouts that reset themselves before a technician arrives.
• A space that holds temperature early and loses it under afternoon load.
• Refrigerant added more than once with no leak found.
• An economizer that seems open, closed, or stuck at the wrong times.
• Comfort complaints from a unit that passes a basic check every time.

Why do intermittent faults come back after a repair?

Usually because they were looked at during the wrong part of the day. A unit that runs cleanly at 9am and locks out at 3pm under full load will keep generating calls until someone watches it at load.

Intermittent faults get expensive because each one creates repeat visits, and each visit replaces a part that may not have been the cause. A weak capacitor, a failing contactor, a condenser fan that overheats, or an economizer sensor reading high can all look fine on a cool morning.

What can a facilities desk gather before the visit?

Pull the unit’s work-order history and note when the complaints happen. Time of day, outdoor temperature, and what the store was doing at the time are often the clues that narrow the search.

A store manager’s note that the sales floor warms up every afternoon around three, or only when the dock doors are open, tells the technician when to be watching. Send it with the work order, along with any fault codes the controller has displayed.

When should rooftop unit testing happen outside trading hours?

Schedule it outside trading hours when the fault needs hours of observation, when roof access crosses the sales floor, when the work is noisy, or when an overnight repair needs confirming before opening.

Our technicians are based across Southern California and Arizona, so an early-morning or after-close window does not mean someone driving the length of the region in the dark. Vanny Weber, our Scheduling and Operations Lead, puts the visit on the board against your trading calendar, and it is recorded in your IVR or work-order system before the store opens.

What gets inspected and tested on a rooftop unit visit?

A thorough inspection and test covers the unit’s history, its electrical, refrigerant, airflow, and controls sides, and its safeties, and ends with a written finding. Readings are compared against manufacturer data.

System	What is checked
History	Work-order history on the unit and fault codes stored in the controller
Electrical	Supply voltage, compressor and motor amperage, capacitors, contactors
Refrigerant	Operating pressures, superheat, subcooling, and a leak search when charge is low
Airflow	Filters, belts, blower speed, coil condition
Safeties	High- and low-pressure switches, limits, condensate float switches
Controls	Economizer sequence, damper travel, sensor readings, schedules
Under load	Operation observed over a full cycle, or readings logged over a longer period

The finding states what failed, why, and what will stop it recurring.

How does one site’s diagnosis help the rest of the portfolio?

When the same unit model shows the same fault at several locations, the pattern points to a shared cause. Fixing that cause once, across the portfolio, costs less than chasing it one store at a time.

That is why the written finding matters beyond a single roof. A facilities desk that can sort work orders by unit model and fault can spot those patterns early. Site documentation and roof access on file for each location keep every visit focused on the unit rather than on getting to it.

What should happen with the readings?

Keep them on the unit’s record. A baseline of pressures, amperages, and temperatures makes the next visit easier to interpret and shows whether a unit is slowly degrading.

Recorded readings also support maintenance programs built on ASHRAE 180 inspection and testing. California’s Title 24 energy code includes economizer requirements for many newer rooftop units, so check current code and manufacturer guidance for each unit. Our guide to economizers on retail rooftop units explains why they so often sit behind intermittent faults, and how a commercial rooftop unit works covers the basics.

What if testing shows the rooftop unit is near end of life?

Sometimes the honest finding is that the unit is near the end of its life. Jessica Bresciani, our Estimating Operations Lead, turns those findings into a quote, whether for the repair or for a replacement.

REE Mechanical Inc. is licensed, bonded and insured, and the same inspection and testing work is available in all six of our Southern California counties and throughout Arizona. See all service areas, including Orange County and San Diego County.

Book a rooftop unit inspection and testing window

Call (800) 742-0910 or contact the service desk with your trading hours. If the unit has stopped cooling outright, place a commercial AC repair call instead.