My AC won't turn on, what do I check? Here is the honest version: what you can safely check yourself in the next five minutes, what a technician usually finds when it is not that, and exactly what it costs to find out.
By Argent Heating & Cooling, Northern Virginia, VA. Updated September 27, 2026.
If this means no cooling in the house: A home with no cooling is treated as urgent and prioritized, often same-day. The emergency button on the booking page gets a callback within 60 seconds.
If one of these fixes it, you owe us nothing and we are glad. If not, the next part is what the visit is for.
Not running. An outdoor unit that will not start with the thermostat calling has a contactor that is not closing or a capacitor that is not starting the motor: the manual's compressor-will-not-run branch is those two parts and the power behind them. Behind a burned contactor is the voltage that burned it: a supply too high or too low, or loose leads at the compressor and contactor that heat every time the unit starts.
Contactor. Contacts pit and weld because of the heat thrown off by a high resistance connection, and once the silver coating has sprayed off them the contactor is on its way out. And it arcs that hard because the unit is running longer and harder than it should, which is what a coil full of debris does to it.
Capacitor. Dirt on the condenser coil makes the air coming over the motor excessively hot, and the electrical parts are what give out first. And the dirt gets to the coil because the air reaching it was never properly filtered.
These are the causes in the manufacturers' troubleshooting charts and the trade handbooks our technicians train on, in plain words. The visit proves which one it is with a meter before anything is replaced.
A compressor cycling on its internal overload is the step before it fails: high head from a dirty coil, a shorted winding, or a starting relay that is not doing its job.
Insects and dirt getting between the points is the other half of it, and blowing the contactor out at the start of each cooling season is what stops it.
$59 on weekdays, $159 evenings and weekends. Published and final, pre-tax, and the price is the price whether we find a loose wire or a bad motor.
Book the $59 visit online Or call (703) 281-6300Real arrival windows, including evenings and weekends. Paying is what confirms the slot; the office calls to confirm the window.