Commercial HVAC
Repair or replace a 16-year-old rooftop unit in Brisbane?
Asked by Amelia Carterin Brisbane, Queensland· 3/17/2026· 1727 views
I'm in Brisbane, Queensland and dealing with a 16-year-old rooftop unit in our single-family home. Over the past few service calls, it has been cooling the space unevenly during occupied hours and we're now noticing the technician who came out last time did not leave any actual readings behind.
One contractor quoted A$2,124 for repair, while another jumped straight to a A$16,370 replacement because of the age. The weather here has been dealing us sudden shoulder-season temperature swings, so I do not want to wait too long, but I also do not want to approve the wrong scope.
If you were comparing bids on this, what would you want checked first? I especially want to know how much weight you would give to economizer settings, supply temperatures, occupancy schedules, and sensor calibration.
commercialrtucontrols
3 Answers
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I would compare how clearly each contractor explains the diagnosis, not just the price. The clearer company ended up being the better hire for us. We had a related issue with our rooftop unit in Brisbane. Once we forced every quote into the same format, the decision got much easier because the weak recommendations stood out immediately.
Isla Walker·3/17/2026
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The price range alone does not tell you enough. Ask what was tested, what failed, and which assumptions are built into the quote. For a rooftop unit that is cooling the space unevenly during occupied hours, the first things I would ask for are economizer settings, supply temperatures, occupancy schedules, and sensor calibration. If the contractor is recommending bigger work, ask them to explain which measurement supports that recommendation and whether they ruled out airflow or controls first. In Brisbane, Queensland, pricing can move around, but the diagnostic process should still be clear.
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Before signing anything, I would ask the technician to show the readings and explain which number actually supports the recommendation. For a rooftop unit that is cooling the space unevenly during occupied hours, the first things I would ask for are economizer settings, supply temperatures, occupancy schedules, and sensor calibration. If the contractor is recommending bigger work, ask them to explain which measurement supports that recommendation and whether they ruled out airflow or controls first. In Brisbane, Queensland, pricing can move around, but the diagnostic process should still be clear.