My AC units will shut off before the temp reaches the set temp. I thought is was my thermostat so I replaced it. No change.
Example. Temp is reading 80. I set temp for 76. The AC goes on. The thermostat (LuxPro) has a blinking indicater when the unit is blowing. The AC stays on for a few minutes dropping the temp to 78. The unit then s off. The indicator on the thermostat still shows that the unit is on but it is clearly off. It stays off for a few minutes and then starts again. Eventually bring the temp down. I place the thermostat in the on position not Auto and the same thing happens. It happened with two different thermostats So I beleave it is the handler or compressor that is the probmem. Any suggestions would be greatly appreaciated.

Do you think by chance you bought a two stage cooling thermostat and you have it wired for 2nd stage only? The two degree swing in the temps is the reason for asking.

You place the thermostat in the on position? This controls the blower. Does the blower shut off also when in the on position? Can you share the model number of the hvac unit and that of the thermostat? T-Top may be correct, you may have a mis-match.

Actually I think I may have figured it out. The unit has a safety that shuts it off if the drain pipe is clogged. I blew out the pipe and it seems to be working OK. I guess it was shutting off when it got clogged, then when it drained enough it would go back on, and then off and then on and so on...

Thanks anyway guys...

There you go... glad you found the problem. NOw blow out the pipe every time you change your filter and prevent it from happening again.