If your building's cooling system is acting up, check the controls before you call a repair company. I learned that lesson after almost signing off on a $14,000 compressor replacement that turned out to be a forgotten Johnson Controls thermostat override. It's the kind of mistake that makes you question every service call you've ever approved.
I'm an office administrator for a mid-size company with three locations and around 400 employees. I handle facilities purchasing—roughly 60 to 80 orders a year across eight vendors. That means I deal with everything from HVAC service contracts to a freezer chest in the cafeteria, a pool heater near the fitness room, and the Samsung refrigerator in the break room.
The building automation system in our main office is from Johnson Controls. The thermostats are Johnson Controls too, and they have an override feature that lets someone temporarily change the schedule and setpoint. It's a useful tool. It's also the source of one of my more expensive headaches.
How I learned to ask what changed
When I took over purchasing in 2020, I treated facility failures like emergencies. Alarm goes off, call the vendor, get a quote, approve it. It felt responsible. But what was best practice in 2020 may not apply in 2025. The industry has moved toward smarter controls, and my job has too. What I mean is that the cheapest repair isn't the one with the lowest quote; it's the one that fixes the actual problem. And often the actual problem is a forgotten setting, a dirty condenser coil, or a fan that stopped moving air.
In 2024, one of our chillers threw a fault alarm. I called our usual vendor, and they said the compressor might need replacing. The quote came in around $14,000. I asked them to dig deeper before I signed the work order. That second look found a stuck override in a conference room zone, which had kept the system running in an unoccupied cooling mode. Once I cleared the override, the fault went away. No compressor needed.
I still kick myself for not checking earlier. If I'd looked at the thermostat schedule before the service call, I'd have spotted the override myself. Now I always ask: "what changed before the problem started?"
The Johnson Controls thermostat override: useful and dangerous
In buildings with a Metasys system, the override function lets you change temperature setpoints and schedules remotely. It's designed for flexibility, like when the executive board needs the conference room cooled to 68 degrees after hours. But if an override is left active, the system keeps running as if the schedule doesn't exist. That can lead to strange alarms, wasted energy, and unnecessary service calls.
The frustrating part is how easy an override is to set and how hard it can be to find. I've never fully understood why the software doesn't make it more obvious, but I've learned to check. If you're already using Johnson Controls thermostats, look for a temporary schedule flag before assuming mechanical failure.
Small equipment follows the same logic
The same troubleshooting approach applies to a Samsung fridge, a freezer chest, or a pool heater. Start with the easy explanations. That phrase, why is my samsung fridge not cooling but freezer works, is one I searched myself when our break room fridge went warm. The freezer was still cold, so the compressor was fine. The cold air just wasn't moving to the fridge section because the evaporator fan was iced over. A quick defrost and a replacement fan fixed it.
A freezer chest losing temperature often comes down to dirty condenser coils. Or rather, it can also come down to door seals and airflow, but clean the coils first. If the coils are covered in dust, heat doesn't dissipate, and the compressor shuts off on thermal overload. Unplug it, vacuum the coils, plug it back in. Sometimes that's the whole repair.
A pool heater that won't turn on? Check water flow first. Most heaters have a pressure switch that won't open the gas valve without enough flow. A clogged pump basket, a dirty filter, or a closed valve can look exactly like a heater failure. It isn't.
Not every repair can be avoided. But more of them can than you'd think.
What about data center cooling?
Data center cooling is a different animal, but the principle holds. I remember reading Reuters coverage in 2025 about Johnson Controls data center cooling work, and the theme was control software and AI optimizing operations, not just bigger chillers. I don't remember every detail, so don't quote me on specifics. But the trend was clear: intelligence is becoming as important as hardware.
For a small team, that's both good and bad. Good because smarter systems catch problems earlier. Bad because you need people who understand them. Five years ago, I could manage equipment with a paper schedule. Now I spend time in the building automation system dashboard.
When to ignore all this advice
I want to be careful here. This worked for us, but we're a mid-size company with predictable schedules and a Johnson Controls system I've had time to learn. Your situation might be different. If you're dealing with refrigerant leaks, stop. That's a licensed tech job. If a compressor is genuinely dead, it's dead. If you have a data center with precision equipment, don't rely on a facilities buyer's checklist. Bring in the specialists.
And every climate is different. A pool heater in a building that uses it year-round will fail differently than ours, where winterizing is part of the routine. So take my experience as a starting point, not a script.
Final thought
Even after all of this, I still second-guess myself before approving a large repair. Hit send and immediately think, did I miss something? The wait for a replacement compressor is stressful. But the more I learn about the control side, the fewer false alarms I approve. And when the fix is something simple—a sticky override, a dusty coil, a fan blade that wasn't turning—there's a quiet satisfaction in knowing the building didn't need a new heart. Just a better look at the controls.
