Why is my air conditioner making a loud noise? 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 one of these fixes it, you owe us nothing and we are glad. If not, the next part is what the visit is for.
Noisy blower. A thumping blower means the wheel is out of balance or the motor mount has come loose, and an unbalanced wheel wears its own bearings out. And the wheel goes out of balance because the return duct is undersized, which is also what takes out door switches.
Condenser fan. A condenser working against a coil it cannot breathe through takes its fan motor with it, and it does it again to the next one. An out of balance blade or a unit that short cycles will do the same thing, and both of those are audible long before the motor gives out.
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.
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 filter too small restricts the whole system, and restriction is what causes the run of repairs behind this.
Most of these bearings are sealed and cannot be oiled at all, so the only maintenance available is keeping what they run against clean.
$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.