Our rented house has what appears to be an older A/C unit for the main living area.

Today for the second time in slightly more than a week, it stopped producing cool air.

Both the fan in the inside unit and the fan on the outside condenser unit seemed to be functioning normally.

The inside unit was not providing any cooling and the air coming off the condenser unit was only ambient temperature.

The first time this happened, I just turned the unit off and back on within a minute and it resumed cooling.

Today, a number of quick restarts didn't have any effect.  But, after being turned off for about an hour I started it up again and normal cooling resumed.

In both instances the unit had been running for at least 6-8 hours.

 

The landlord has said they will send someone to inspect/repair/replace as needed.

 

I just wish to have a better understanding of A/C so I can better handle any future issues.

Today I assumed that the unit was not going to function until repaired.  Our inside temp rose from 28 to 33 in short order.

 

What is the most likely cause of these temporary failures?

 

Probably needs a clean and possibly needs topping up with refrigerant? The current heat and humidity is also making aircon's work harder.

 

Also note that turning an aircon off and back on quickly is not good for the compressor, more so if an older unit. Ideally it's best to cycle power over 2 or 3 minutes.

I had the same problem with my 8 year old Samsung.  Oddly enough, basically the same fix.

When it began blowing warm air, I would turn off the main power switch (not the power button on the remote) and let it rest minimum 5 minutes.  When turned back on, it usually blew cool air.

Sometimes it would work ok for several days, sometimes malfunctioning several times a day. 

I could never figure out the real problem or why a 5 minute power cut cured it.

Finally, it just quit and I replaced it. 

I'd be looking at the capacitor on the compressor motor as a first suspect.

 

Second in line would be the thermostat.

6 hours ago, NanLaew said:

Probably needs a clean and possibly needs topping up with refrigerant? The current heat and humidity is also making aircon's work harder.

 

Also note that turning an aircon off and back on quickly is not good for the compressor, more so if an older unit. Ideally it's best to cycle power over 2 or 3 minutes.

OR maybe it has A virus a new strain called covid-air.

There are 3 electric motors involved . 1 for the inside unit, 1 for the cooling  fan on the outside unit, 1 for the compressor. If the compressor motor stops it may have a thermal cutoff which resets after enough time to cool down.

yeah could be stat issue, but likely going out on lp due to being low on gas and resetting once powered down.