HVAC & air-con
Split systems, ducted units, controls and condensate.
Split-system air-con not running at all
A split-system (head unit + outdoor condenser) is completely dead — no response from the remote/controller — pointing at supply, isolator, controller, or the indoor PCB.
Air-con tripping the power
An air-con unit trips its breaker or safety switch — on start, when the compressor kicks in, or randomly — pointing at the compressor, an earth fault, or the supply/protection.
Air-con runs but isn't cooling (electrical checks)
The unit runs (fan blows) but doesn't cool — from an electrical standpoint, checking whether the compressor/outdoor unit is actually being commanded and powered before handing to refrigeration.
Ducted air-con system has no power / won't start
A ducted system (roof/cupboard fan unit + zones/controller) is dead or won't start — pointing at the dedicated supply/isolator, the controller, zone motors, or the unit's PCB.
Air-con condensate pump not working / unit shut down on overflow
An aircon has shut down on a condensate overflow/float switch, or its condensate pump isn't running — water isn't being removed, so the unit stops to prevent overflow.
HVAC thermostat/controller blank or unresponsive
A heating/cooling thermostat or controller is blank or unresponsive, so the system won't run — pointing at the controller's power (often low-voltage from the unit), wiring, or the controller itself.
Commercial exhaust / ventilation fan not running
A larger exhaust/ventilation fan (carpark, kitchen, plant room) won't run — pointing at its starter/control, supply, motor, or an interlock with a control system.