The system is on. The outdoor unit is making noise. The air at the register is barely cooler than the hallway. That is the July call in Englewood, and it is a different failure from a system that will not start at all.
Four causes account for most of these visits. They feel the same from the couch.
The capacitor quit
The capacitor is the small part that kicks the compressor and the fan motor into motion. Salt and a long cooling season wear it out. You hear a hum or a click at the condenser, then the fan sits still or the compressor never joins in. Inside, the air goes warm because nothing is moving heat.
Leave it off. Pushing the fan blade with a stick to “help it start” can spin the motor for a minute and then take the compressor with it. A meter tells us whether the capacitor is out of range or the compressor itself is done.
The charge is low
Warm air, ice on the copper lines, or a hiss at the outdoor unit point at refrigerant that is no longer at the level on the nameplate. Refrigerant does not get “used up.” If it is low, it left through a leak. On this coast the leak is often the coil, where salt has pitted the tubing.
We measure the pressure. We do not add a hardware-store can and hope. A top-off without finding the leak is a repair that lasts until the next hot week.
Air cannot get through
A filter that has not been changed, an evaporator packed with dust, or a supply duct that came loose in the attic all starve the coil. The system runs long, the house stays warm, and the coil may freeze. Ice is the clue. Turn the system off and let it thaw before anyone adds refrigerant to a frozen coil. The charge is often fine. The air path is not.
The drain shut it down
Cooling pulls water out of the air, and that water leaves through a small line that grows algae here. When the line blocks, a float switch kills the cooling so the closet does not flood. The thermostat still says “on.” The house heats up. People replace thermostats for this.
Water near the air handler, or a system that runs a few minutes and quits, is this failure until we prove otherwise. Clear the line and the cooling comes back. Ignore it and the next call is a wet ceiling.
If the outdoor unit is humming and the house is warm, shut the system off and call. Repeated start attempts are what finishes a struggling compressor. We test the capacitor, the charge, the airflow, and the drain, in that order, and the price is in writing before a part goes in.
Related: AC repair in Englewood and emergency AC repair when the house cannot wait until morning.
