Carrier 38BYC, vintage 1999. 4 ton. Old but in decent shape. Last week, about 2PM, setpoint was 74 degrees as usual. Inside temp rose to 77 and we noticed it. Blower blowing warm air. Outside unit completely off. Turned the tstat up, went to get my tools. Checked the breaker, it was fine, cycled it anyway. After maybe 3-4 minutes, I ran the tstat back down then went outside to do some troubleshooting. This time the unit was running fine. It continued to do so. Then, a week later, at literally the same time, the SAME thing happened again. It's like it just didn't feel like turning on right then.. 5 minutes later it was fine.
Called my A/C guy, he added a hard start kit. He's generally good at what he does, when I can't fix it I call him and he does a fine job.
Now, here we are 4 days later. Been working fine. Guess what, it's 2:30PM - tstat calls for cool, registers blowing warm air, outside unit off. Stayed like that for about 3 minutes. Went to get my tools, as I was walking over to the A/C it started up.Then all was well.
I do have to point out that the sun is in a position to shine directly on the A/C electrical panel cover hiding the contactor and circuit board, etc. unit for a few hours just before this time of day, if that matters. Seems like it's just moved into the shade when things get better. A/C guy says it's not related, but he's somewhat stumped. Why else would this always be happening at 2:30-3PM?
The charge is ok, was checked recently. Once it starts the air is indeed nice and cold. It gets hottest about 5PM and it was 102 outside the other day with many people in the house. We cranked the tstat down from it's usual 74 to 72 and it had no problem holding temp at all.
Contactor was replaced last season. Connections are tight.
What the heck is going on?