An AC that won't start usually has a power, control or electrical-component fault. Common causes are a tripped breaker, a thermostat set wrong or with dead batteries, a failed capacitor or contactor, a safety switch (like a full condensate float) that's cut power, or a compressor problem. A breaker that trips repeatedly is a real electrical fault — never just keep resetting it.
Start with the safe checks
- Thermostat: set to Cool, setpoint below room temperature, fresh batteries.
- Power: check the breaker hasn't tripped and any isolator switch is on. Reset a tripped breaker once — if it trips again, stop.
- Condensate safety switch: a full drain pan can trip a float switch and cut power by design — a blocked drain may be the real cause.
- Outdoor unit: confirm it isn't obstructed or overheating.
Important: if the breaker trips again after one reset, stop and call a technician. A repeatedly tripping breaker means a short, an overloaded compressor or a wiring fault — resetting it repeatedly is a fire and equipment risk.
Faults that need an engineer
- Failed run/start capacitor: a very common no-start cause — the compressor or fan can't get going.
- Contactor failure: the relay that powers the outdoor unit sticks or burns out.
- Compressor fault or seized motor: can draw high current and trip the breaker.
- Wiring, control board or transformer faults.
How an AGM engineer fixes it
We test the electrical supply, thermostat, capacitor, contactor and compressor, measure starting current, find why a breaker is tripping, and replace the failed component — safely and to standard. You get a clear diagnosis and fixed quote. In peak summer we offer priority and same-day visits; see emergency HVAC service.
Frequently asked questions
A repeatedly tripping breaker means a genuine electrical fault — a short, a failing capacitor, or a compressor drawing too much current. Reset it once; if it trips again, stop and call a technician, as repeated resets are dangerous.
Check the thermostat setting and batteries, the breaker and isolator switch, and whether a condensate float switch has cut power because the drain is blocked. If those are fine, it's likely an electrical component.
The capacitor gives the motor the jolt it needs to start. Heat — very common in Qatar — degrades capacitors over time, and a failed one is one of the most frequent no-start causes. It's a quick fix for a technician.
You can safely check the thermostat, breaker and drain. Anything involving capacitors, contactors, the compressor or wiring must be done by a licensed technician.