Some extended running during peak summer heat is normal, but a unit that never cycles off, regardless of outdoor temperature, usually points to an undersized system, low refrigerant, or a thermostat issue rather than expected behaviour.
When Long Runtimes Are Expected
During the hottest part of a UAE summer, an AC unit working to maintain a large temperature difference between indoor and outdoor air will naturally run for extended periods, and that alone isn't cause for concern. The key distinction is whether the unit is still reaching the set temperature eventually, even if it takes longer than usual.
When Constant Running Signals a Problem
If the unit runs continuously but the room never actually reaches the thermostat's set temperature, that's a sign of a real issue — commonly low refrigerant, a unit that's undersized for the space, or a dirty coil restricting heat transfer. A thermostat that's miscalibrated or poorly located, sensing a warmer spot than the rest of the room, can also cause this.
What to Check Before Calling for Repair
Confirming the filter is clean and vents aren't blocked rules out the simplest causes first. If the room still isn't reaching temperature after that, it's worth having refrigerant levels and system sizing checked rather than assuming the unit simply needs to run longer.
If this sounds like what's happening with your unit, our Central AC Repair page covers exactly how we handle it, or you can message us directly for a same-day assessment.
Frequently Asked Questions
How long should an AC run per cycle in summer?
There's no fixed number, since it depends on outdoor temperature, room size and insulation, but the unit should still be reaching the set temperature within a reasonable time, not running indefinitely without effect.
Does non-stop running mean the AC is broken?
Not always — check whether the room is actually cooling first, since a unit working hard but succeeding isn't the same as one running constantly without result.
Can a bigger AC unit fix constant running?
Sometimes, if the current unit is genuinely undersized, but it's worth ruling out refrigerant or maintenance issues first since those are cheaper to fix than replacing the unit.