How we know this
This job isn’t in the U.S. government’s occupational survey yet, so this page carries no official pay figures. Everything below is drawn from published job descriptions and industry guides, each one linked at the foot of the page. The work described is real and sourced. What’s missing is the survey’s rating of which parts of the job matter most — so read this as a picture of the work, not a ranked list.
Think you get this job?Six quick questions on how it really works — with a hint and the reason behind every answer.
Test yourself →The work, task by task
These are the real jobs-to-be-done, not a wish list. Each task shows where we found it, and the prompt underneath is written for that exact task.
Diagnose system failures using specialized tools
+Diagnose the rooftop unit that failed during last night's call by tracing the fault, log voltage and…
Diagnose system failures using specialized tools
+Diagnose the rooftop unit that failed during last night's call by tracing the fault, log voltage and continuity at the compressor and control board, measure suction and head pressures, note temperatures across the coil, and report probable cause with parts list and safety risks.
The tools that do the workdigital multimetersmanifold gauge setsweb
Pasted it? Good. When the reply comes back, push once: ask it to sharpen the weakest part. — Did this prompt help?
Perform routine maintenance on HVAC systems
+Perform the quarter-mile preventive check on the office split systems: clean and oil blower assemblies, clear…
Perform routine maintenance on HVAC systems
+Perform the quarter-mile preventive check on the office split systems: clean and oil blower assemblies, clear condensate drains, check and tighten electrical terminals, record amp draw and thermostat calibration, then hand the owner a one-page checklist and next-service date.
The tools that do the workinfrared thermometersdigital multimetersweb
Pasted it? Good. When the reply comes back, push once: ask it to sharpen the weakest part. — Did this prompt help?
Replace filters, coils, and other components
+Replace the clogged air filter, remove and inspect the outdoor coil, swap the failing expansion valve and…
Replace filters, coils, and other components
+Replace the clogged air filter, remove and inspect the outdoor coil, swap the failing expansion valve and install the new blower motor assembly, test run the system to confirm airflow and coil temperatures, and note serial numbers of replaced parts for the service ticket.
The tools that do the workinfrared thermometersweb
Pasted it? Good. When the reply comes back, push once: ask it to sharpen the weakest part. — Did this prompt help?
Test electrical connections and control systems
+Test all control circuits on the unit called in by the property manager: verify continuity and voltage on the…
Test electrical connections and control systems
+Test all control circuits on the unit called in by the property manager: verify continuity and voltage on the thermostat wiring, bench the contactor and relay coils, log control board signals during a start cycle, and list any control module failures with recommended next steps.
The tools that do the workdigital multimetersweb
Pasted it? Good. When the reply comes back, push once: ask it to sharpen the weakest part. — Did this prompt help?
Inspect and test HVAC systems for proper operation
+Inspect the tenant's HVAC before the summer peak: run the unit through heat and cool cycles, record operating…
Inspect and test HVAC systems for proper operation
+Inspect the tenant's HVAC before the summer peak: run the unit through heat and cool cycles, record operating pressures and temperatures, check filter condition and belt tension, verify thermostat accuracy, and produce a one-page pass/fail report with prioritized fixes and cost estimates.
The tools that do the workmanifold gauge setsinfrared thermometersweb
Pasted it? Good. When the reply comes back, push once: ask it to sharpen the weakest part. — Did this prompt help?
Says who?
These are the pages we read to build this. Open any of them and check us.
Related careers
Same family of work — each with its own tasks and prompts.
The LLOS Work Atlas is the world's largest evidenced task library — a map of human work, with a ready prompt behind every task. 1,774 careers · every task named by the sources that witnessed it — O*NET, ESCO, real job descriptions, Wikipedia — and the deepest tasks by several at once. And it is honest about limits: where AI cannot help, the map says so.
The rest of the map
Same library, five ways in.
Copyright © LLOS.ai · 2026 — original pedagogy, voice, and design — all rights reserved.
Built on public evidence: O*NET®, ESCO, Wikipedia, U.S. Bureau of Labor Statistics, ILOSTAT. All sources & licenses
Built on public evidence: O*NET®, ESCO, Wikipedia, U.S. Bureau of Labor Statistics, ILOSTAT. All sources & licenses